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

With no annotations, the description carries the full burden. It states the core behavior (parsing PEM) and extracted fields but does not disclose potential errors (e.g., invalid PEM format) or that the input must be a valid X.509 certificate. It's adequate but not thorough.

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?

The description is a single sentence of 10 words, front-loaded with the verb and key resource. It is concise and without wasted words, though it could benefit from slight expansion without losing efficiency.

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?

Given that parsing X.509 certificates has complexity and there is no output schema, the description is minimal. It lists some fields but does not hint at the output structure (e.g., JSON object), leaving the agent uncertain about the return format. More context is needed.

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?

The schema has one required parameter 'pem' with 0% description coverage. The description does not add meaning beyond the parameter name; it only mentions 'PEM' without specifying the expected format (e.g., valid PEM string with headers). For a single parameter, more detail would help.

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 clearly states the verb 'Parse', the resource 'X.509 certificate PEM', and lists specific fields extracted (subject, issuer, validity, SAN, fingerprint). This distinguishes it from sibling tools like pem_decode and ssl_cert_fetch.

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?

No guidance is provided on when to use this tool versus alternatives. Despite having siblings like ssl_cert_fetch (which fetches certificates) and pem_decode, no usage context or exclusions are mentioned.

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