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

Annotations already cover safety (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the description's added value is the disclosure of the four verification dimensions and the two verdict outcomes (match vs. modified), which an agent needs to interpret results. It does not say what happens when the capture is missing or when verification fails to run, leaving a minor gap.

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 resource and the enumerated checks, followed by the outcome vocabulary. No filler and nothing repeated from the name or title.

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 a rich annotation set, an output schema, and a single fully documented parameter, the description only needs to explain what is verified and what verdicts mean — both are present. Missing only edge-case behavior (unverifiable/corrupt package, unknown capture_id), which keeps it short of a 5.

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?

Only one parameter, and the schema already documents it at 100% coverage including the format example and pattern. The description's phrase 'a stored ... evidence package' weakly implies the capture_id refers to a previously stored capture, adding little beyond the schema; baseline 3 is appropriate.

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 (checks/verifies) applied to a specific resource (a stored ProofSnap evidence package) and enumerates exactly what is checked: manifest signature, per-file SHA-256, timestamps, and issuer authenticity. It does not, however, distinguish itself from near-siblings such as lookup_manifest or compare_captures, which an agent must still disambiguate by name alone.

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?

Usage is only implied: you verify a package that has already been stored, and the parenthetical 'match (unchanged) or modified' hints at the integrity-checking scenario. There is no explicit when-to-use/when-not guidance and no routing to alternatives like compare_captures for diffing two captures.

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