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

With no annotations provided, the description carries the full burden, and it explicitly declares read-only behavior and lists three operations it does NOT perform. This goes beyond the input schema and prevents false assumptions about revocation or key matching.

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: the first covers purpose and outputs, the second covers limitations. No wasted words, and the main behavior is front-loaded.

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 single-parameter, read-only inspection tool with no output schema, the description enumerates all return values and key limitations. Nothing an agent needs to decide whether or how to call it is omitted.

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 already provides 100% coverage for the single pem parameter and even specifies the required PEM markers. The description adds context about what the parsed output contains, but does not need to add parameter-level semantics.

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 names a specific action ('Parse') and resource ('PEM-encoded X.509 certificate') and enumerates the exact returned fields (subject, issuer, validity window, expired status). It also distances itself from trust-chain verification, revocation, and key matching, so an agent can distinguish cert_inspect from general validation tools such as verify.

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 description explicitly states what the tool will not do, establishing when it is inappropriate for trust-chain or revocation checks. It does not name a specific alternative tool, but the exclusions give clear situational guidance.

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