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

No annotations are provided, so the description carries full responsibility. It discloses that the tool is free, stores no personal information (only request words), catalogues requests, and that repeated requests lead to data being built. This is substantial behavioral transparency for a tool with no annotation support.

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, information-dense sentence that front-loads the key facts (free, no payment) and clearly explains the behavior. It's not overly long and each clause adds value, though it could be broken into shorter sentences for readability. Overall it's well-structured and efficient.

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 one-parameter tool with no output schema or annotations, the description covers what the user provides, what they get back, and privacy implications. It's complete enough for an agent to call correctly without additional ambiguity.

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%, so the parameter 'need' is already documented with examples. The description adds context (free-form, any topic) but no technical syntax above the schema. This matches the baseline for high coverage, so a 3 is 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?

The description clearly states the action: describe the data you're trying to buy and get back whether the service supplies it, with the MCP endpoint if so. It explicitly distinguishes from siblings by noting 'anything, not just groceries,' making the tool's role as a general inquiry endpoint obvious.

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?

Provides clear guidance: 'call it whenever you cannot find a source for something.' This defines when to use the tool and implies it's a fallback when other tools don't apply. It doesn't explicitly mention alternatives, but the context is sufficient and it's not misleading.

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