Verify a GitHub claim

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-call profile is covered structurally. The description adds a genuinely useful auth prerequisite ('Set GITHUB_TOKEN for private repos'), but says nothing about behavior on missing refs, rate limits, or whether a failed check is an error or a negative verdict.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the core purpose, and every clause earns its place by naming a distinct check mode or a prerequisite. The colon-separated enumeration is dense but scannable, with no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description carries the burden of explaining what comes back, and it never says whether the result is a boolean, a verdict with evidence, or an error on a failed check. The check-to-parameter mapping is also left implicit, so a caller can still mis-invoke it despite otherwise adequate coverage.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 80%, so the schema already documents pr, ref, repo, and claim; the baseline of 3 applies. The description adds modest value by implying which check each input answers (PR-based vs. ref-based), but never states explicitly that `pr` is required for pr_merged/checks_passing while `ref` is required for commit_exists/checks_passing — a pairing the agent must infer.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb and resource ('Check what GitHub actually says') and then enumerates the three exact checks it performs — PR merge status, CI check status, and commit/branch existence — which map directly onto the check enum. This clearly differentiates it from siblings like verify_npm and verify_url, which cover other verification surfaces.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The enumerated checks give clear context for when each mode applies (verifying a merge claim vs. a CI claim vs. a pushed-commit claim), and the private-repo token note signals the prerequisite. There is no explicit when-not guidance or named alternative for overlapping checks, so it falls short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.