Summary

The GitHub guard does not fully cover 2 write operation(s) reachable via the GitHub CLI that have no MCP tool counterpart and no guard entry. This means the guard has no pre-emptive classification for these operations if a corresponding MCP tool is added to the GitHub MCP server in the future.

• MCP tools scanned: 80 (from github-mcp-server toolsnaps)
• CLI write command categories scanned: ~12 (pr, issue, repo, release, gist, workflow, run, label, project, secret, variable, run)
• Guard-covered write tools (tools.rs): 42 in WRITE_OPERATIONS + 10 in READ_WRITE_OPERATIONS
• Tools with explicit DIFC rules (tool_rules.rs): all read tools covered; write tools use default handling
• MCP tool classification gaps: 0 — all 80 upstream MCP tools are properly classified
• MCP tool labeling gaps: 0 — all read tools have explicit match arms in apply_tool_labels
• New CLI-only gaps found this run: 2

GitHub CLI-Only Gaps

These write operations are reachable via the GitHub CLI but have no corresponding MCP tool and no guard entry. The guard has archive_repository as a pre-emptive entry (consistent with the pattern of pre-emptive entries for anticipated future MCP tools), but the symmetric unarchive_repository and the related rename_repository are absent.

Why these matter

• rename_repository — does not match any prefix pattern (create_*, delete_*, merge_*, update_*, lock_*, unlock_*). Without an explicit entry, if the MCP server adds a rename_repository tool, it would bypass write-classification and be treated as a read operation.
• unarchive_repository — symmetric to archive_repository, which IS already in WRITE_OPERATIONS as a pre-emptive entry. The lack of the inverse creates an asymmetry: archiving is guarded but un-archiving is not. The unarchive_* prefix is also not matched by any pattern.

Suggested fix for tools.rs

pub const WRITE_OPERATIONS: &[&str] = &[
    // ... existing entries ...

    // Pre-emptive entries for anticipated future MCP tools (no equivalent tool today)
    "archive_repository",    // gh repo archive
    "unarchive_repository",  // gh repo unarchive — symmetric to archive_repository
    "rename_repository",     // gh repo rename — breaks integrations; not matched by update_*
    // ... other pre-emptive entries ...
];

Stale Guard Entries (bonus)

The following tools are in WRITE_OPERATIONS or READ_WRITE_OPERATIONS but no longer appear in the upstream github-mcp-server toolsnaps. They do have GitHub CLI equivalents (so they are not stale by strict definition), but they may represent tools that were consolidated or renamed in the MCP server:

These entries are harmless (they won't match real tool calls if the tool no longer exists), but cleaning them up would improve maintainability.

References

• github-mcp-server toolsnaps
• GitHub CLI repo commands
• guard tools.rs
• guard tool_rules.rs
• Run: §23717785343

Generated by GitHub Guard Coverage Checker (MCP + CLI) · ◷

• expires on Apr 12, 2026, 8:09 PM UTC