mutualAuthBuildCertificate

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

With no annotations, the description carries the burden of behavioral disclosure. It reveals that the issuer's Ed25519 private key signs the canonical JCS form, a non-obvious technical detail affecting the output. It also states that the tool returns a signed object, implying no side effects. Could mention security handling but is adequate.

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 two sentences with no filler. The first sentence front-loads the main action, and the second efficiently describes the return value and the signature mechanism.

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?

The tool has 13 parameters and no output schema or annotations. The description clarifies the return value's purpose but does not describe the certificate structure or error conditions. The schema's field descriptions help, but the description alone leaves gaps around how parameters relate to the signed object.

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% with all 13 parameters documented, so the baseline is 3. The description adds some context by explaining the issuer private key's role in signing the JCS form, but does not meaningfully expand on the other parameters beyond the schema.

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 phrase 'Build and sign' and names the resource 'mutual-auth certificate' with the target 'agent or information system'. This clearly distinguishes it from sibling tools like mutualAuthVerifyTrustBundle and mutualAuthDeriveSession, which focus on verification and key derivation.

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 states the certificate is 'ready to carry into a handshake', giving clear context for when to use the tool. It does not explicitly name alternatives or exclusions, but the purpose of building a cert before a handshake is unambiguous.

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