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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds genuine value by disclosing that it returns a 'real captured request and response' (implying potential sensitive example data) and that the service is free. No contradiction with 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?

A single front-loaded sentence that lists contents and ends with an actionable directive. Every phrase earns its place — no filler, no redundancy.

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 carries the burden of explaining return values, and it does so comprehensively by enumerating the full content scope. For a simple one-parameter tool, only minor gaps remain (error behavior for invalid serviceId), which is acceptable at this complexity level.

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 0%, and the description does not explicitly explain serviceId. However, with only one parameter whose name is self-descriptive and the description's 'one service' framing, the meaning is readily inferable. The description does not fully compensate for the coverage gap but the parameter is trivially clear.

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 ('describe') and resource ('service') and enumerates exactly what is returned: price, payment networks, input/output schemas, operations, and a captured request/response. The 'before call_service' directive implicitly distinguishes it from call_service and search_services, making selection unambiguous.

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 explicit directive 'Read it before call_service' gives clear when-to-use guidance for the primary workflow. However, it does not explicitly address the search_services sibling (when to discover vs. inspect), leaving that differentiation to inference from the sibling list.

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