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[finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole #13573

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Open
[finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole#13573
Bug
Labels
domain:skillspm:queuepriority:p1High: required for production / M2tooling

Description

@zhuangjianguo
zhuangjianguo
opened on Aug 31, 2026

Filed unassigned by the domain:engine lane PM. Recording only — no severity asserted, routing is triage's. Surfaced on #13382 during dispatch; the implementing seat noticed the discrepancy and I re-measured it independently from the PM side.

Measured, both channels, same issue, same minute

Subject: issue #13382.

channelbody delivered
MCP issue_read (method: "get")453 charscut mid-sentence
unauthenticated REST GET /repos/{owner}/{repo}/issues/133822173 charscomplete

1,720 characters — 79.2% of the card — were dropped, with no truncation marker, no ellipsis, and no field indicating the body was partial.

The MCP body ends at:

1. `GET /api/v1/data/

The first 120 characters of what was silently dropped:

<object>/<id>` → 响应里 `updated_at: "2026-08-30T10:19:25.947Z"`(ISO,带毫秒)
2. `PATCH /api/v1/data/<object>/<id>`,body 带 `exp

Why this one is worth a card

The truncated 79% was not boilerplate. It contained the entire minimal reproduction, the root-cause analysis naming normaliseVersionToken, and the blast-radius statement — 「所有 postgres 生产部署的所有对象编辑都受影响,爆炸半径是整个 Console 编辑链路」. A seat that read this p1 card through MCP and started work would have had the symptom and none of the evidence, and nothing in the response would have told it so.

A truncation that announces itself costs a re-read. A silent one costs a wrong plan built on a partial card, and the reader cannot know to distrust it.

The workaround is narrower than the one currently in circulation

My own dispatch order for #13382 told the seat "the API truncates — go read the issue page on the web". That advice was wrong in a way worth correcting: this is an MCP-channel artifact, not an API-wide one. Plain unauthenticated REST returns the whole body. So the cheap remedy for any seat is a REST read, not a browser.

Scope NOT established

  • Measured on one issue. Whether the cut is a fixed byte budget, a token budget, a per-response cap shared with other fields, or something content-dependent is UNMEASURED — 453 is not asserted to be a constant.
  • Whether issue_read's other methods (get_comments, get_sub_issues) truncate the same way is not tested here. Comments on rest/OCC: postgres 驱动下乐观锁必现假冲突 409 —— normaliseVersionToken 对 Date 做 String() 丢毫秒后与 ISO 字符串严格比较 #13382 came back complete, but that is one sample and they are shorter.
  • Whether the same applies to pull_request_read bodies is not tested — though PR bodies far longer than 453 chars have come back whole in this session, which suggests the mechanism is not a simple universal cap and deserves a real measurement rather than my inference.

Related, and DISTINCT from each of them

This is a fifth mechanism in the same family, not a duplicate:

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[finding] MCP `issue_read` silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole · Issue #13573 · objectstack-ai/objectstack · GitHub
      Skip to content
      [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole #13573
      Open
      Bug
      Open
      [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole#13573
      Bug
      Labels
      domain:skillspm:queuepriority:p1High: required for production / M2tooling
      Description
      @zhuangjianguo
      zhuangjianguo
      opened on Aug 31, 2026
      Filed unassigned by the domain:engine lane PM. Recording only — no severity asserted, routing is triage's. Surfaced on #13382 during dispatch; the implementing seat noticed the discrepancy and I re-measured it independently from the PM side.
      Measured, both channels, same issue, same minute
      Subject: issue #13382.
      channelbody delivered
      MCP issue_read (method: "get")453 charscut mid-sentence
      unauthenticated REST GET /repos/{owner}/{repo}/issues/133822173 charscomplete
      1,720 characters — 79.2% of the card — were dropped, with no truncation marker, no ellipsis, and no field indicating the body was partial.
      The MCP body ends at:
      1. `GET /api/v1/data/

      The first 120 characters of what was silently dropped:
      <object>/<id>` → 响应里 `updated_at: "2026-08-30T10:19:25.947Z"`(ISO,带毫秒)
2. `PATCH /api/v1/data/<object>/<id>`,body 带 `exp

      Why this one is worth a card
      The truncated 79% was not boilerplate. It contained the entire minimal reproduction, the root-cause analysis naming normaliseVersionToken, and the blast-radius statement — 「所有 postgres 生产部署的所有对象编辑都受影响,爆炸半径是整个 Console 编辑链路」. A seat that read this p1 card through MCP and started work would have had the symptom and none of the evidence, and nothing in the response would have told it so.
      A truncation that announces itself costs a re-read. A silent one costs a wrong plan built on a partial card, and the reader cannot know to distrust it.
      The workaround is narrower than the one currently in circulation
      My own dispatch order for #13382 told the seat "the API truncates — go read the issue page on the web". That advice was wrong in a way worth correcting: this is an MCP-channel artifact, not an API-wide one. Plain unauthenticated REST returns the whole body. So the cheap remedy for any seat is a REST read, not a browser.
      Scope NOT established
      • Measured on one issue. Whether the cut is a fixed byte budget, a token budget, a per-response cap shared with other fields, or something content-dependent is UNMEASURED — 453 is not asserted to be a constant.
      • Whether issue_read's other methods (get_comments, get_sub_issues) truncate the same way is not tested here. Comments on rest/OCC: postgres 驱动下乐观锁必现假冲突 409 —— normaliseVersionToken 对 Date 做 String() 丢毫秒后与 ISO 字符串严格比较 #13382 came back complete, but that is one sample and they are shorter.
      • Whether the same applies to pull_request_read bodies is not tested — though PR bodies far longer than 453 chars have come back whole in this session, which suggests the mechanism is not a simple universal cap and deserves a real measurement rather than my inference.
      Related, and DISTINCT from each of them
      This is a fifth mechanism in the same family, not a duplicate:
      Metadata
      Metadata
      Assignees
      No one assigned
        Labels
        domain:skillspm:queuepriority:p1High: required for production / M2tooling
        Type
        Bug
        Projects
        No projects
          Milestone
          No milestone
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          None yet
          Development
          No branches or pull requests
          Issue actions
          
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[finding] MCP `issue_read` silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole · Issue #13573 · objectstack-ai/objectstack · GitHub
          Skip to content
          [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole #13573
          Open
          Bug
          Open
          [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole#13573
          Bug
          Labels
          domain:skillspm:queuepriority:p1High: required for production / M2tooling
          Description
          @zhuangjianguo
          zhuangjianguo
          opened on Aug 31, 2026
          Filed unassigned by the domain:engine lane PM. Recording only — no severity asserted, routing is triage's. Surfaced on #13382 during dispatch; the implementing seat noticed the discrepancy and I re-measured it independently from the PM side.
          Measured, both channels, same issue, same minute
          Subject: issue #13382.
          channelbody delivered
          MCP issue_read (method: "get")453 charscut mid-sentence
          unauthenticated REST GET /repos/{owner}/{repo}/issues/133822173 charscomplete
          1,720 characters — 79.2% of the card — were dropped, with no truncation marker, no ellipsis, and no field indicating the body was partial.
          The MCP body ends at:
          1. `GET /api/v1/data/

          The first 120 characters of what was silently dropped:
          <object>/<id>` → 响应里 `updated_at: "2026-08-30T10:19:25.947Z"`(ISO,带毫秒)
2. `PATCH /api/v1/data/<object>/<id>`,body 带 `exp

          Why this one is worth a card
          The truncated 79% was not boilerplate. It contained the entire minimal reproduction, the root-cause analysis naming normaliseVersionToken, and the blast-radius statement — 「所有 postgres 生产部署的所有对象编辑都受影响,爆炸半径是整个 Console 编辑链路」. A seat that read this p1 card through MCP and started work would have had the symptom and none of the evidence, and nothing in the response would have told it so.
          A truncation that announces itself costs a re-read. A silent one costs a wrong plan built on a partial card, and the reader cannot know to distrust it.
          The workaround is narrower than the one currently in circulation
          My own dispatch order for #13382 told the seat "the API truncates — go read the issue page on the web". That advice was wrong in a way worth correcting: this is an MCP-channel artifact, not an API-wide one. Plain unauthenticated REST returns the whole body. So the cheap remedy for any seat is a REST read, not a browser.
          Scope NOT established
          • Measured on one issue. Whether the cut is a fixed byte budget, a token budget, a per-response cap shared with other fields, or something content-dependent is UNMEASURED — 453 is not asserted to be a constant.
          • Whether issue_read's other methods (get_comments, get_sub_issues) truncate the same way is not tested here. Comments on rest/OCC: postgres 驱动下乐观锁必现假冲突 409 —— normaliseVersionToken 对 Date 做 String() 丢毫秒后与 ISO 字符串严格比较 #13382 came back complete, but that is one sample and they are shorter.
          • Whether the same applies to pull_request_read bodies is not tested — though PR bodies far longer than 453 chars have come back whole in this session, which suggests the mechanism is not a simple universal cap and deserves a real measurement rather than my inference.
          Related, and DISTINCT from each of them
          This is a fifth mechanism in the same family, not a duplicate:
          Metadata
          Metadata
          Assignees
          No one assigned
            Labels
            domain:skillspm:queuepriority:p1High: required for production / M2tooling
            Type
            Bug
            Projects
            No projects
              Milestone
              No milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
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[finding] MCP `issue_read` silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole · Issue #13573 · objectstack-ai/objectstack · GitHub
              Skip to content
              [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole #13573
              Open
              Bug
              Open
              [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole#13573
              Bug
              Labels
              domain:skillspm:queuepriority:p1High: required for production / M2tooling
              Description
              @zhuangjianguo
              zhuangjianguo
              opened on Aug 31, 2026
              Filed unassigned by the domain:engine lane PM. Recording only — no severity asserted, routing is triage's. Surfaced on #13382 during dispatch; the implementing seat noticed the discrepancy and I re-measured it independently from the PM side.
              Measured, both channels, same issue, same minute
              Subject: issue #13382.
              channelbody delivered
              MCP issue_read (method: "get")453 charscut mid-sentence
              unauthenticated REST GET /repos/{owner}/{repo}/issues/133822173 charscomplete
              1,720 characters — 79.2% of the card — were dropped, with no truncation marker, no ellipsis, and no field indicating the body was partial.
              The MCP body ends at:
              1. `GET /api/v1/data/

              The first 120 characters of what was silently dropped:
              <object>/<id>` → 响应里 `updated_at: "2026-08-30T10:19:25.947Z"`(ISO,带毫秒)
2. `PATCH /api/v1/data/<object>/<id>`,body 带 `exp

              Why this one is worth a card
              The truncated 79% was not boilerplate. It contained the entire minimal reproduction, the root-cause analysis naming normaliseVersionToken, and the blast-radius statement — 「所有 postgres 生产部署的所有对象编辑都受影响,爆炸半径是整个 Console 编辑链路」. A seat that read this p1 card through MCP and started work would have had the symptom and none of the evidence, and nothing in the response would have told it so.
              A truncation that announces itself costs a re-read. A silent one costs a wrong plan built on a partial card, and the reader cannot know to distrust it.
              The workaround is narrower than the one currently in circulation
              My own dispatch order for #13382 told the seat "the API truncates — go read the issue page on the web". That advice was wrong in a way worth correcting: this is an MCP-channel artifact, not an API-wide one. Plain unauthenticated REST returns the whole body. So the cheap remedy for any seat is a REST read, not a browser.
              Scope NOT established
              • Measured on one issue. Whether the cut is a fixed byte budget, a token budget, a per-response cap shared with other fields, or something content-dependent is UNMEASURED — 453 is not asserted to be a constant.
              • Whether issue_read's other methods (get_comments, get_sub_issues) truncate the same way is not tested here. Comments on rest/OCC: postgres 驱动下乐观锁必现假冲突 409 —— normaliseVersionToken 对 Date 做 String() 丢毫秒后与 ISO 字符串严格比较 #13382 came back complete, but that is one sample and they are shorter.
              • Whether the same applies to pull_request_read bodies is not tested — though PR bodies far longer than 453 chars have come back whole in this session, which suggests the mechanism is not a simple universal cap and deserves a real measurement rather than my inference.
              Related, and DISTINCT from each of them
              This is a fifth mechanism in the same family, not a duplicate:
              Metadata
              Metadata
              Assignees
              No one assigned
                Labels
                domain:skillspm:queuepriority:p1High: required for production / M2tooling
                Type
                Bug
                Projects
                No projects
                  Milestone
                  No milestone
                  Relationships
                  None yet
                  Development
                  No branches or pull requests
                  Issue actions
                  
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[finding] MCP `issue_read` silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole · Issue #13573 · objectstack-ai/objectstack · GitHub
                  Skip to content
                  [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole #13573
                  Open
                  Bug
                  Open
                  [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole#13573
                  Bug
                  Labels
                  domain:skillspm:queuepriority:p1High: required for production / M2tooling
                  Description
                  @zhuangjianguo
                  zhuangjianguo
                  opened on Aug 31, 2026
                  Filed unassigned by the domain:engine lane PM. Recording only — no severity asserted, routing is triage's. Surfaced on #13382 during dispatch; the implementing seat noticed the discrepancy and I re-measured it independently from the PM side.
                  Measured, both channels, same issue, same minute
                  Subject: issue #13382.
                  channelbody delivered
                  MCP issue_read (method: "get")453 charscut mid-sentence
                  unauthenticated REST GET /repos/{owner}/{repo}/issues/133822173 charscomplete
                  1,720 characters — 79.2% of the card — were dropped, with no truncation marker, no ellipsis, and no field indicating the body was partial.
                  The MCP body ends at:
                  1. `GET /api/v1/data/

                  The first 120 characters of what was silently dropped:
                  <object>/<id>` → 响应里 `updated_at: "2026-08-30T10:19:25.947Z"`(ISO,带毫秒)
2. `PATCH /api/v1/data/<object>/<id>`,body 带 `exp

                  Why this one is worth a card
                  The truncated 79% was not boilerplate. It contained the entire minimal reproduction, the root-cause analysis naming normaliseVersionToken, and the blast-radius statement — 「所有 postgres 生产部署的所有对象编辑都受影响,爆炸半径是整个 Console 编辑链路」. A seat that read this p1 card through MCP and started work would have had the symptom and none of the evidence, and nothing in the response would have told it so.
                  A truncation that announces itself costs a re-read. A silent one costs a wrong plan built on a partial card, and the reader cannot know to distrust it.
                  The workaround is narrower than the one currently in circulation
                  My own dispatch order for #13382 told the seat "the API truncates — go read the issue page on the web". That advice was wrong in a way worth correcting: this is an MCP-channel artifact, not an API-wide one. Plain unauthenticated REST returns the whole body. So the cheap remedy for any seat is a REST read, not a browser.
                  Scope NOT established
                  • Measured on one issue. Whether the cut is a fixed byte budget, a token budget, a per-response cap shared with other fields, or something content-dependent is UNMEASURED — 453 is not asserted to be a constant.
                  • Whether issue_read's other methods (get_comments, get_sub_issues) truncate the same way is not tested here. Comments on rest/OCC: postgres 驱动下乐观锁必现假冲突 409 —— normaliseVersionToken 对 Date 做 String() 丢毫秒后与 ISO 字符串严格比较 #13382 came back complete, but that is one sample and they are shorter.
                  • Whether the same applies to pull_request_read bodies is not tested — though PR bodies far longer than 453 chars have come back whole in this session, which suggests the mechanism is not a simple universal cap and deserves a real measurement rather than my inference.
                  Related, and DISTINCT from each of them
                  This is a fifth mechanism in the same family, not a duplicate:
                  Metadata
                  Metadata
                  Assignees
                  No one assigned
                    Labels
                    domain:skillspm:queuepriority:p1High: required for production / M2tooling
                    Type
                    Bug
                    Projects
                    No projects
                      Milestone
                      No milestone
                      Relationships
                      None yet
                      Development
                      No branches or pull requests
                      Issue actions
                      
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[finding] MCP `issue_read` silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole · Issue #13573 · objectstack-ai/objectstack · GitHub
                      Skip to content
                      [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole #13573
                      Open
                      Bug
                      Open
                      [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole#13573
                      Bug
                      Labels
                      domain:skillspm:queuepriority:p1High: required for production / M2tooling
                      Description
                      @zhuangjianguo
                      zhuangjianguo
                      opened on Aug 31, 2026
                      Filed unassigned by the domain:engine lane PM. Recording only — no severity asserted, routing is triage's. Surfaced on #13382 during dispatch; the implementing seat noticed the discrepancy and I re-measured it independently from the PM side.
                      Measured, both channels, same issue, same minute
                      Subject: issue #13382.
                      channelbody delivered
                      MCP issue_read (method: "get")453 charscut mid-sentence
                      unauthenticated REST GET /repos/{owner}/{repo}/issues/133822173 charscomplete
                      1,720 characters — 79.2% of the card — were dropped, with no truncation marker, no ellipsis, and no field indicating the body was partial.
                      The MCP body ends at:
                      1. `GET /api/v1/data/

                      The first 120 characters of what was silently dropped:
                      <object>/<id>` → 响应里 `updated_at: "2026-08-30T10:19:25.947Z"`(ISO,带毫秒)
2. `PATCH /api/v1/data/<object>/<id>`,body 带 `exp

                      Why this one is worth a card
                      The truncated 79% was not boilerplate. It contained the entire minimal reproduction, the root-cause analysis naming normaliseVersionToken, and the blast-radius statement — 「所有 postgres 生产部署的所有对象编辑都受影响,爆炸半径是整个 Console 编辑链路」. A seat that read this p1 card through MCP and started work would have had the symptom and none of the evidence, and nothing in the response would have told it so.
                      A truncation that announces itself costs a re-read. A silent one costs a wrong plan built on a partial card, and the reader cannot know to distrust it.
                      The workaround is narrower than the one currently in circulation
                      My own dispatch order for #13382 told the seat "the API truncates — go read the issue page on the web". That advice was wrong in a way worth correcting: this is an MCP-channel artifact, not an API-wide one. Plain unauthenticated REST returns the whole body. So the cheap remedy for any seat is a REST read, not a browser.
                      Scope NOT established
                      • Measured on one issue. Whether the cut is a fixed byte budget, a token budget, a per-response cap shared with other fields, or something content-dependent is UNMEASURED — 453 is not asserted to be a constant.
                      • Whether issue_read's other methods (get_comments, get_sub_issues) truncate the same way is not tested here. Comments on rest/OCC: postgres 驱动下乐观锁必现假冲突 409 —— normaliseVersionToken 对 Date 做 String() 丢毫秒后与 ISO 字符串严格比较 #13382 came back complete, but that is one sample and they are shorter.
                      • Whether the same applies to pull_request_read bodies is not tested — though PR bodies far longer than 453 chars have come back whole in this session, which suggests the mechanism is not a simple universal cap and deserves a real measurement rather than my inference.
                      Related, and DISTINCT from each of them
                      This is a fifth mechanism in the same family, not a duplicate:
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[finding] MCP `issue_read` silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole · Issue #13573 · objectstack-ai/objectstack · GitHub
                          Skip to content
                          [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole #13573
                          Open
                          Bug
                          Open
                          [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole#13573
                          Bug
                          Labels
                          domain:skillspm:queuepriority:p1High: required for production / M2tooling
                          Description
                          @zhuangjianguo
                          zhuangjianguo
                          opened on Aug 31, 2026
                          Filed unassigned by the domain:engine lane PM. Recording only — no severity asserted, routing is triage's. Surfaced on #13382 during dispatch; the implementing seat noticed the discrepancy and I re-measured it independently from the PM side.
                          Measured, both channels, same issue, same minute
                          Subject: issue #13382.
                          channelbody delivered
                          MCP issue_read (method: "get")453 charscut mid-sentence
                          unauthenticated REST GET /repos/{owner}/{repo}/issues/133822173 charscomplete
                          1,720 characters — 79.2% of the card — were dropped, with no truncation marker, no ellipsis, and no field indicating the body was partial.
                          The MCP body ends at:
                          1. `GET /api/v1/data/

                          The first 120 characters of what was silently dropped:
                          <object>/<id>` → 响应里 `updated_at: "2026-08-30T10:19:25.947Z"`(ISO,带毫秒)
2. `PATCH /api/v1/data/<object>/<id>`,body 带 `exp

                          Why this one is worth a card
                          The truncated 79% was not boilerplate. It contained the entire minimal reproduction, the root-cause analysis naming normaliseVersionToken, and the blast-radius statement — 「所有 postgres 生产部署的所有对象编辑都受影响,爆炸半径是整个 Console 编辑链路」. A seat that read this p1 card through MCP and started work would have had the symptom and none of the evidence, and nothing in the response would have told it so.
                          A truncation that announces itself costs a re-read. A silent one costs a wrong plan built on a partial card, and the reader cannot know to distrust it.
                          The workaround is narrower than the one currently in circulation
                          My own dispatch order for #13382 told the seat "the API truncates — go read the issue page on the web". That advice was wrong in a way worth correcting: this is an MCP-channel artifact, not an API-wide one. Plain unauthenticated REST returns the whole body. So the cheap remedy for any seat is a REST read, not a browser.
                          Scope NOT established
                          • Measured on one issue. Whether the cut is a fixed byte budget, a token budget, a per-response cap shared with other fields, or something content-dependent is UNMEASURED — 453 is not asserted to be a constant.
                          • Whether issue_read's other methods (get_comments, get_sub_issues) truncate the same way is not tested here. Comments on rest/OCC: postgres 驱动下乐观锁必现假冲突 409 —— normaliseVersionToken 对 Date 做 String() 丢毫秒后与 ISO 字符串严格比较 #13382 came back complete, but that is one sample and they are shorter.
                          • Whether the same applies to pull_request_read bodies is not tested — though PR bodies far longer than 453 chars have come back whole in this session, which suggests the mechanism is not a simple universal cap and deserves a real measurement rather than my inference.
                          Related, and DISTINCT from each of them
                          This is a fifth mechanism in the same family, not a duplicate:
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                            Labels
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[finding] MCP `issue_read` silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole · Issue #13573 · objectstack-ai/objectstack · GitHub
                              Skip to content
                              [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole #13573
                              Open
                              Bug
                              Open
                              [finding] MCP issue_read silently truncated an issue body to 20.8% — 1,720 of 2,173 chars dropped with no marker, and REST returns it whole#13573
                              Bug
                              Labels
                              domain:skillspm:queuepriority:p1High: required for production / M2tooling
                              Description
                              @zhuangjianguo
                              zhuangjianguo
                              opened on Aug 31, 2026
                              Filed unassigned by the domain:engine lane PM. Recording only — no severity asserted, routing is triage's. Surfaced on #13382 during dispatch; the implementing seat noticed the discrepancy and I re-measured it independently from the PM side.
                              Measured, both channels, same issue, same minute
                              Subject: issue #13382.
                              channelbody delivered
                              MCP issue_read (method: "get")453 charscut mid-sentence
                              unauthenticated REST GET /repos/{owner}/{repo}/issues/133822173 charscomplete
                              1,720 characters — 79.2% of the card — were dropped, with no truncation marker, no ellipsis, and no field indicating the body was partial.
                              The MCP body ends at:
                              1. `GET /api/v1/data/

                              The first 120 characters of what was silently dropped:
                              <object>/<id>` → 响应里 `updated_at: "2026-08-30T10:19:25.947Z"`(ISO,带毫秒)
2. `PATCH /api/v1/data/<object>/<id>`,body 带 `exp

                              Why this one is worth a card
                              The truncated 79% was not boilerplate. It contained the entire minimal reproduction, the root-cause analysis naming normaliseVersionToken, and the blast-radius statement — 「所有 postgres 生产部署的所有对象编辑都受影响,爆炸半径是整个 Console 编辑链路」. A seat that read this p1 card through MCP and started work would have had the symptom and none of the evidence, and nothing in the response would have told it so.
                              A truncation that announces itself costs a re-read. A silent one costs a wrong plan built on a partial card, and the reader cannot know to distrust it.
                              The workaround is narrower than the one currently in circulation
                              My own dispatch order for #13382 told the seat "the API truncates — go read the issue page on the web". That advice was wrong in a way worth correcting: this is an MCP-channel artifact, not an API-wide one. Plain unauthenticated REST returns the whole body. So the cheap remedy for any seat is a REST read, not a browser.
                              Scope NOT established
                              • Measured on one issue. Whether the cut is a fixed byte budget, a token budget, a per-response cap shared with other fields, or something content-dependent is UNMEASURED — 453 is not asserted to be a constant.
                              • Whether issue_read's other methods (get_comments, get_sub_issues) truncate the same way is not tested here. Comments on rest/OCC: postgres 驱动下乐观锁必现假冲突 409 —— normaliseVersionToken 对 Date 做 String() 丢毫秒后与 ISO 字符串严格比较 #13382 came back complete, but that is one sample and they are shorter.
                              • Whether the same applies to pull_request_read bodies is not tested — though PR bodies far longer than 453 chars have come back whole in this session, which suggests the mechanism is not a simple universal cap and deserves a real measurement rather than my inference.
                              Related, and DISTINCT from each of them
                              This is a fifth mechanism in the same family, not a duplicate:
                              Metadata
                              Metadata
                              Assignees
                              No one assigned
                                Labels
                                domain:skillspm:queuepriority:p1High: required for production / M2tooling
                                Type
                                Bug
                                Projects
                                No projects
                                  Milestone
                                  No milestone
                                  Relationships
                                  None yet
                                  Development
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                                  Issue actions