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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, so the safety profile is covered. The description adds genuinely useful non-annotation context: it is free (no cost/auth barrier) and returns verdict, scores, price per call, and measured latency. It does not discuss pagination or result caps, but with an output schema present that is minor.

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 short sentences, zero waste, with the core purpose front-loaded. Each sentence adds a distinct piece of information (what, cost, what it returns, where to use it next) rather than restating the title.

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 zero-required-parameter read-only search tool with a full output schema, the description covers everything an agent needs: scope, cost, return shape, and the workflow handoff to get_review. Return-value detail is legitimately delegated to the output schema.

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 three parameters (q, limit, category) documented and an enum on category, so the schema carries parameter meaning fully. The description adds no syntax or format guidance beyond what the schema provides, making the baseline 3 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?

States a specific verb (Search) and resource (independently-tested directory of agent-payable services), and scopes it concretely with the examples x402 endpoints, MCP servers, AI APIs. It also routes clearly away from ambiguity by naming get_review as the downstream sibling, so an agent can place it in the workflow without opening any schema.

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?

Explicitly says what it is for: 'find the exact `service` name for get_review,' which gives the agent a clear trigger. It stops short of stating when NOT to use it or naming alternative discovery siblings (e.g. get_bundle), so it is clear context rather than full when/when-not routing.

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