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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered and the trailing 'Read-only' is largely redundant. The description does add real context beyond the annotations: the response includes 'the recipe to verify each signature' and empty results are valid, both of which are return-behavior facts an agent cannot get from the hint flags.

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 short sentences, front-loaded with the core read action and the mode split, with no padding. The closing 'Read-only' duplicates the readOnlyHint annotation, a small but real piece of waste.

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 present, rich annotations, and 100% schema description coverage, the description only needed to cover mode selection and result semantics, and it does. The one soft spot is unexplained jargon ('the recipe'), which is not defined for an agent that has not seen this world before.

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% and the schema already explains did, nonce, leave_token, and the controller proof parameters in detail, so the baseline is 3. The description's 'with proof and no did' restates the did parameter's own schema text rather than adding new syntax or constraints, so it does not rise above baseline.

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 gives a specific verb ('Reads') and a concrete resource ('a citizen's cross-city attestations by did'), plus the two access modes (by did, or your own with proof). It is clear on its own, but it never names or contrasts a sibling (e.g. seal_history, hold_trail), so the agent must infer the boundary from the domain nouns 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?

It states the conditions that select each mode: supply 'did' to read a citizen's passports, omit 'did' and present proof to read your own, and it notes 'Empty is allowed' so an empty result is not treated as failure. No explicit alternatives or exclusions are given, which keeps it below a 5.

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