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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely new traits beyond them: results are cached only, the call is free, and the response may include optional x402 certification offers. It stops short of describing staleness or pagination limits.

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?

Four dense sentences, front-loaded with the free/read-only constraint and the default-vs-query usage split. It is slightly redundant in restating read-only alongside the annotations, but no sentence 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 7-parameter, zero-coverage tool with no output schema, the description covers the primary mode of use and hints at the return contents (certification offers) but leaves the six filtering/sorting parameters and the shape of a returned server entry unaddressed.

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 coverage is 0%, so the description must carry parameter meaning. It explains the query parameter well (searched across names, URLs, repositories, and observed tool names) and implies a stability-oriented default, but sort, limit, source, min_tools, min_pass_rate, and min_observations receive no explanation at all.

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 and resource: find currently reachable public MCP servers from ProofRail's autonomous catalog, with the added scope of cached, PASS/ok candidates. The purpose is unambiguous, but no sibling (mcp_radar_snapshot, mcp_radar_changes) is named or contrasted, so an agent must infer the boundary itself.

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?

Gives explicit branching guidance: call with no arguments for the most stable current PASS/ok candidates, or supply query for task/capability search. That is clear when-to-use context, but there is no when-not-to-use and no routing to the sibling radar tools.

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