Find Something on the Shelf

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, but the description adds substantial behavioral context: it's free, requires no account, results stay in shelf order, nothing is ranked or recommended, a listing is not a stock check, and invalid lookups return a free next_step. This goes far beyond the annotations and gives the agent essential expectations.

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 two tight sentences that front-load the core action and options, then pack in essential behavioral caveats. Every sentence carries weight, with no redundant phrasing or fluff. It is efficient 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?

Given the 3 optional parameters, full schema coverage, and an output schema, the description covers all necessary context: when to use, what filters exist, what the rows contain, ordering, limitations, and error behavior. An agent can invoke this tool correctly without additional inference.

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%, so each parameter is already documented. The description provides a high-level summary (filter by price or text, or item_id) but adds little new meaning beyond what the schema says. The item_id replacement semantics are already in the schema description. Thus the description meets the baseline for full coverage.

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 states a specific verb ('Find'), resource ('an item in the catalog'), and the scope ('filter the shelf by price or text, or pass item_id'). It explicitly distinguishes from the buy_* siblings by saying 'Find an item before using buy_*'. This is a clear, differentiating purpose statement.

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 gives clear guidance on when to use this tool ('before using buy_*') and how to invoke it (filter by price/text or pass item_id). It also notes limitations ('not a stock check') and error behavior. It does not explicitly name alternative non-buy tools, but the context is strong enough for an agent to select it appropriately.

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