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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly discloses that the service is free, that requests are catalogued, that nothing identifying is stored, and that only the words of the request are kept. This is unusually transparent for a request tool and covers privacy and data-handling behavior beyond the obvious purpose.

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 single, front-loaded sentence that opens with the key free-of-cost detail, then states the purpose and outcome, and closes with privacy guarantees. Every clause contributes meaning, with no fluff. It is concise and well-structured.

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 single-parameter tool with no output schema, the description tells the agent exactly what to expect: whether the service supplies the data and the endpoint if so. It also covers side effects (cataloguing) and privacy. Nothing essential is missing for an agent to decide to call this tool and know what will happen.

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 schema already describes the only parameter 'need' as 'What you are looking for' with an example. The description adds value by clarifying the format: 'Describe in your own words' and the scope 'anything, not just feeds'. This goes beyond the schema's bare definition, so a score above the baseline 3 is warranted.

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 clearly states the verb ('request'), the resource ('data'), and the outcome ('get back whether we operate a service that supplies it, with the MCP endpoint if so'). It distinguishes itself from siblings by emphasizing 'anything, not just feeds', which signals it is a broad inquiry tool rather than a feed-specific discovery or read operation. The purpose is 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 description implies when to use it: when you want to ask about data availability in free-form. The phrase 'not just feeds' subtly contrasts with feed-specific siblings (discover_feeds), and the context 'trying to buy' suggests a pre-purchase inquiry. However, it does not explicitly state when not to use it or name alternatives, so it stops short of a 5.

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