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

Annotations already cover read-only/idempotent/closed-world safety, so the description's job is to add context — and it does: it discloses that results come from a *local snapshot* (a staleness/data-currency caveat), that absence of a match is not a safety proof, and that no account or token is required. These are traits an agent cannot get from the structured fields.

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?

Four short, labelled blocks (purpose, when-to-use, notes, example) with the core capability front-loaded. Every sentence — including the staleness and no-token notes — carries actionable information with zero 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 an output schema, full annotation coverage, and 100% schema description coverage, the description fills the remaining gaps: data source currency, the interpretation caveat on empty results, auth requirements, and a usage example. Nothing an agent needs to call this correctly is missing.

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 100%, so the baseline is 3; the description earns a bump by supplying a concrete example argument showing ecosystem/name/version nesting and reinforcing that versions must be exact (no ranges). It still adds no per-field semantics beyond the schema, so not a 5.

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?

States a specific verb and resource: checking exact npm/PyPI/Go versions against a local GitHub Reviewed Advisory snapshot, and names the output shape (affected ranges, fixed versions, links). The emphasis on 'exact' versions implicitly distinguishes it from the sibling check_semver_range, and the scope is unambiguous.

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 'When to use' line gives clear triggering contexts (lockfile review, dependency upgrade, version-specific security question) and adds a valuable negative guarantee ('No match does not prove a package is safe'). It does not name alternatives like check_semver_range or validate_package_json, so explicit routing is left to inference.

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