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

Annotations already cover safety (readOnly, idempotent, openWorld), yet the description still adds valuable inclusion semantics: approved plus under-review endpoints that passed the facilitator's 402 check, with hidden and unchecked entries excluded. The prompt-injection warning about merchant-written descriptions is genuinely useful behavior guidance; only the exact return shape is left unspecified.

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 core scope is front-loaded in the first clause, with listing rules, the injection caveat, and the payment pointer following in order of need. The opening sentence is dense and stacks several clauses, but no sentence is filler.

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?

With no output schema, the description still tells the agent what will appear in results (which approval states, which endpoints are excluded, how under-review items are marked), and where to go next to transact. That is sufficient to call and interpret 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?

Schema coverage is 100% and the single query param is documented there (name/description/URL match, maxLength 100), so the description adds little beyond 'optionally filtered by a search word'. Since it correctly signals that the parameter is optional (0 required params), it avoids misleading the agent.

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 (list services registered with the Priors facilitator that accept x402 USDG payments on Robinhood Chain) plus the optional filter. An agent can distinguish this from find_sellers, find_jobs, or find_agents 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?

Clear context for use: discovery of payable services, with an explicit routing note to the local @priors/mcp pay_url (see how_to_connect) for actually paying. It doesn't explicitly name the sibling to use for non-service lookups, so alternatives are only implied.

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