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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. Beyond that, the description discloses the full status vocabulary (current, revised, superseded, hash_mismatch, version_not_found, not_found) and the non-obvious caveat that not_found on a legal citation only means it is absent from this dataset. It doesn't say what an agent should do on hash_mismatch, which is the one behavioral 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?

Three compact sentences, front-loaded with the accepted input forms and the verification hint, with the status vocabulary at the end. Some of the parameter phrasing duplicates the schema text, which is minor waste but 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?

For a two-parameter read-only lookup with an output schema, the description covers input forms, the hash-verification use case, and the status meanings, so nothing essential for calling it is missing. The only omission is guidance on how to react to a hash_mismatch or superseded result, which an agent would have to infer.

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 description coverage is 100%, so both parameters are already fully documented, including the sha256 pattern and the id@vN / /v/N version syntax. The description's parameter content largely restates the schema ('Pass content_hash ... to confirm the content is unchanged') rather than adding new semantics, so the 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?

The description opens with a specific verb ('Checks a citation you were handed') and enumerates the exact input forms accepted: evidence ID with optional @vN, canonical URL with optional /v/N, or a legal citation string. That enumeration makes it clearly distinguishable from get_evidence (which retrieves) and search_evidence (which finds).

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 phrase 'a citation you were handed' plus 'Pass content_hash from the cite_as block to confirm the content is unchanged' gives a clear triggering context for verification work. It does not explicitly say when to prefer get_evidence instead, so the alternative-routing advice is implied rather than stated.

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