Guard coverage: classify `create_agent_task` as read-write and blocked by Copilot · Pull Request #3139 · github/gh-aw-mcpg

Copilot · 2026-04-04T00:36:18Z

gh agent-task create (POST copilot-api/agents/swe/v1/jobs/{owner}/{repo}) had no guard entry despite causing real repo mutations (branch creation + PR). Per agent instructions, this operation is read-write (reads task context, writes branch/PR) and unsupported (unconditionally blocked).

`tools.rs`

Added "create_agent_task" to READ_WRITE_OPERATIONS — operation is classified as "read-write" in label_resource
Added "create_agent_task" to is_blocked_tool() — DIFC evaluator always denies it via blocked_integrity override, consistent with transfer_repository, archive_repository, etc.

`labels/tool_rules.rs`

Added match arm for create_agent_task applying repo-visibility secrecy before the blocked_integrity override kicks in at label_resource

// tools.rs
pub const READ_WRITE_OPERATIONS: &[&str] = &[
    // ...existing entries...
    "create_agent_task", // gh agent-task create — blocked: unsupported agent operation
];

pub fn is_blocked_tool(tool_name: &str) -> bool {
    matches!(
        tool_name,
        "transfer_repository" | "archive_repository" | "unarchive_repository"
            | "rename_repository" | "create_agent_task"
    )
}

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

example.com
- Triggering command: /tmp/go-build2534278610/b340/launcher.test /tmp/go-build2534278610/b340/launcher.test -test.testlogfile=/tmp/go-build2534278610/b340/testlog.txt -test.paniconexit0 -test.timeout=10m0s /tmp/go-build2534278610/b223/vet.cfg flib/difflib.go 64/src/runtime/cgo x_amd64/compile (dns block)
invalid-host-that-does-not-exist-12345.com
- Triggering command: /tmp/go-build2534278610/b322/config.test /tmp/go-build2534278610/b322/config.test -test.testlogfile=/tmp/go-build2534278610/b322/testlog.txt -test.paniconexit0 -test.timeout=10m0s rev-�� ternal/engine/wazevo/backend/isa/amd64/abi_entry_amd64.s (dns block)
nonexistent.local
- Triggering command: /tmp/go-build2534278610/b340/launcher.test /tmp/go-build2534278610/b340/launcher.test -test.testlogfile=/tmp/go-build2534278610/b340/testlog.txt -test.paniconexit0 -test.timeout=10m0s /tmp/go-build2534278610/b223/vet.cfg flib/difflib.go 64/src/runtime/cgo x_amd64/compile (dns block)
slow.example.com
- Triggering command: /tmp/go-build2534278610/b340/launcher.test /tmp/go-build2534278610/b340/launcher.test -test.testlogfile=/tmp/go-build2534278610/b340/testlog.txt -test.paniconexit0 -test.timeout=10m0s /tmp/go-build2534278610/b223/vet.cfg flib/difflib.go 64/src/runtime/cgo x_amd64/compile (dns block)
this-host-does-not-exist-12345.com
- Triggering command: /tmp/go-build2534278610/b349/mcp.test /tmp/go-build2534278610/b349/mcp.test -test.testlogfile=/tmp/go-build2534278610/b349/testlog.txt -test.paniconexit0 -test.timeout=10m0s go_.�� @v1.1.3/ascii/eq-errorsas @v1.1.3/ascii/va-ifaceassert x_amd64/vet -I /tmp/go-build132/usr/bin/runc -I x_amd64/vet -I g_.a 0098554/b151/ x_amd64/vet -o /dev/null (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

…pported) Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/375134d9-0241-4dd0-bd71-841099bfb1d7 Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot

Pull request overview

Adds guard coverage for gh agent-task create by classifying create_agent_task as a read-write operation and unconditionally blocking it, while ensuring repo-visibility secrecy is applied during labeling.

Changes:

Classify create_agent_task as "read-write" and add it to the unconditional blocklist.
Apply repo-visibility secrecy for create_agent_task in tool label rules.
Add a unit test asserting create_agent_task is read-write and blocked.

Show a summary per file

File	Description
guards/github-guard/rust-guard/src/tools.rs	Adds `create_agent_task` classification (read-write + blocked) and a unit test for the classification/blocking.
guards/github-guard/rust-guard/src/labels/tool_rules.rs	Adds labeling rule to apply repo-visibility secrecy for `create_agent_task` prior to blocked integrity override in `label_resource`.

Copilot's findings

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Files reviewed: 2/2 changed files
Comments generated: 3

Copilot · 2026-04-04T03:56:33Z

guards/github-guard/rust-guard/src/tools.rs

    "issue_write",
    "sub_issue_write",
    "update_gist",
+    // Pre-emptive entries for anticipated future MCP tools (no equivalent tool today)


The comment says these are “pre-emptive entries … (no equivalent tool today)”, but create_agent_task is an actual supported tool name being classified/blocked in this PR. Please reword this header comment so it doesn’t imply the tool doesn’t exist (it’s misleading for future readers reviewing guard coverage).

Suggested change

// Pre-emptive entries for anticipated future MCP tools (no equivalent tool today)

// Additional guarded read-write operations, including supported tool mappings that remain blocked

Copilot · 2026-04-04T03:56:34Z

guards/github-guard/rust-guard/src/tools.rs

+            !is_write_operation("create_agent_task"),
+            "create_agent_task should not be in WRITE_OPERATIONS (it is in READ_WRITE_OPERATIONS)"


The test asserts !is_write_operation("create_agent_task"), which bakes in the current implementation detail that read-write ops are excluded from is_write_operation. Since is_write_operation is only used as part of operation classification (and could reasonably be broadened to include read-write ops in the future), consider removing this assertion or instead asserting that the labeled operation is "read-write" / that it’s not explicitly listed in WRITE_OPERATIONS.

Suggested change

!is_write_operation("create_agent_task"),

"create_agent_task should not be in WRITE_OPERATIONS (it is in READ_WRITE_OPERATIONS)"

!WRITE_OPERATIONS.contains(&"create_agent_task"),

"create_agent_task should not be explicitly listed in WRITE_OPERATIONS (it is in READ_WRITE_OPERATIONS)"

Copilot · 2026-04-04T03:56:34Z

guards/github-guard/rust-guard/src/labels/tool_rules.rs

+        // === Copilot coding-agent task (blocked: unsupported agent operation) ===
+        "create_agent_task" => {
+            // Creates a Copilot coding-agent job that modifies repo branches and opens a PR.
+            // Blocked via is_blocked_tool(); secrecy applied so the resource is correctly
+            // classified before the integrity override in label_resource.
+            // S = S(repo); I = blocked (override applied in label_resource)
+            secrecy = apply_repo_visibility_secrecy(&owner, &repo, repo_id, secrecy, ctx);
+        }


apply_tool_labels now has a dedicated create_agent_task arm to apply repo-visibility secrecy, but there’s no unit test exercising this new labeling behavior. Please add a test (similar to test_apply_tool_labels_transfer_repository_secrecy_inherits_repo_visibility in labels/mod.rs) to ensure the create_agent_task arm is hit and continues to apply repo-visibility secrecy as intended.

Initial plan

b75c75f

Copilot AI assigned Copilot and lpcox Apr 4, 2026

Copilot started work on behalf of lpcox April 4, 2026 00:36 View session

Copilot AI linked an issue Apr 4, 2026 that may be closed by this pull request

[guard-coverage] Guard coverage gap: 1 new CLI write operation not covered (gh agent-task create) #3132

Closed

Guard coverage: add create_agent_task as read/write and blocked (unsu…

44a4fc3

…pported) Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/375134d9-0241-4dd0-bd71-841099bfb1d7 Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix guard coverage gap for new CLI write operation~~ Guard coverage: classify create_agent_task as read-write and blocked Apr 4, 2026

Copilot AI requested a review from lpcox April 4, 2026 00:43

Copilot finished work on behalf of lpcox April 4, 2026 00:43

github-actions bot mentioned this pull request Apr 4, 2026

[smoke-safeoutputs] Smoke Safe-Outputs PRs: 23967758946 #3147

Closed

lpcox marked this pull request as ready for review April 4, 2026 03:52

Copilot AI review requested due to automatic review settings April 4, 2026 03:52

lpcox merged commit 893fa02 into main Apr 4, 2026
17 checks passed

lpcox deleted the copilot/guard-coverage-fix-cli-write-operation branch April 4, 2026 03:52

Copilot started reviewing on behalf of lpcox April 4, 2026 03:52 View session

Copilot AI reviewed Apr 4, 2026

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github-actions bot mentioned this pull request Apr 4, 2026

Smoke Test: Copilot - 23970757612 #3152

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Guard coverage: classify `create_agent_task` as read-write and blocked#3139

Guard coverage: classify `create_agent_task` as read-write and blocked#3139
lpcox merged 2 commits intomainfrom
copilot/guard-coverage-fix-cli-write-operation

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	// Pre-emptive entries for anticipated future MCP tools (no equivalent tool today)
	// Additional guarded read-write operations, including supported tool mappings that remain blocked

		!is_write_operation("create_agent_task"),
		"create_agent_task should not be in WRITE_OPERATIONS (it is in READ_WRITE_OPERATIONS)"

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tools.rs

labels/tool_rules.rs

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Copilot AI commented Apr 4, 2026 •

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`tools.rs`

`labels/tool_rules.rs`