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

Annotations already declare readOnlyHint=true and the description is consistent with a pure check (no contradiction). It adds real value by naming the two verification axes (signature of agentborn, validity period), but omits the critical behavioral question for a verifier: does an invalid certificate raise an error or come back as a result, and is any reason/diagnostic returned? With no output schema, that gap matters.

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?

One compact sentence with the resource and both checks front-loaded and no filler. It is arguably too short for the amount of undocumented structure, but nothing in it is wasted.

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 tool taking an opaque nested object with zero schema documentation and no output schema, the description should cover the expected certificate shape and the shape of the verdict. Neither is present, so an agent cannot reliably build the input or interpret the result beyond guessing.

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?

There is one required parameter at 0% schema description coverage, and the schema is a bare nested object with additionalProperties {}, so nothing is documented structurally. The description only says the input is a certificate JSON from another agent; it never indicates which fields the certificate must contain (signature, issuer, expiry, subject agent id), leaving the caller unable to construct a valid payload.

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 (verify/check) and resource (a birth certificate JSON supplied by another agent), plus the two things it checks: the agentborn signature and whether the certificate is still valid. That is enough to separate it from every sibling (check_subdomain, lookup_agent, get_profile, etc.), none of which inspect certificates, though the phrasing is terse and partly in Vietnamese while the tool ecosystem reads as English.

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 clause 'do agent khác đưa' (supplied by another agent) implies the scenario — validating credentials handed over by a peer agent — but there is no explicit when-to-use/when-not, no mention of what to do when verification fails, and no named alternative. Usage is inferable rather than stated.

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