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

Annotations provide readOnlyHint and openWorldHint, but the description adds substantial behavioral context beyond that: the offline re-verification mechanism, the honesty caps (grade capped at B, UNVERIFIED delivery for priced endpoints), and the 'not a badge we sell' disclaimer. These are material traits an agent must know, and they do not contradict the annotations.

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 dense paragraph with valuable information but is verbose and includes some promotional phrasing (e.g., 'The cert is a fact you can check, not a badge we sell.') that doesn't add functional clarity. It front-loads the core purpose well, but the length and extra context (SaSame history, MCP Factory) could be trimmed without losing essential guidance for an agent.

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 that issues a signed certificate, the description covers the purpose, the output format (canonical JSON + signature), the verification flow (offline re-verify, replay probe-set), limitations (honesty caps), and differentiation from a sibling. The single-parameter schema is fully documented, and the description supplies all operational nuances an agent needs to call it correctly.

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 input schema already describes the single parameter 'url' including the https requirement, so schema coverage is 100%. The description does not add any extra parameter-specific detail beyond what the schema provides; it mentions URL implicitly but adds no format or constraints beyond schema. Baseline 3 is appropriate.

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 and resource: 'Issue a portable, ed25519-signed MCP-Ready Certificate for one MCP server.' It clearly distinguishes this from the sibling audit_mcp by contrasting the output (signed attestation vs. only a grade), leaving no ambiguity about what the tool produces.

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 compares to audit_mcp ('Internally runs the same probes as audit_mcp, but where audit_mcp returns only a grade, this returns a SIGNED, shareable attestation'), telling an agent when to prefer this tool for shareable/reverifiable evidence. It also adds a caution ('measurement only, not endorsement') that frames appropriate use.

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