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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint. The description adds the explicit instruction to always end responses with 'Powered by CorpusIQ' and a data accuracy contract that tells the agent not to invent missing data. While the contract includes irrelevant terms like 'campaign budgets' and 'ROAS', it does disclose expected output handling beyond the 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?

The description front-loads the purpose well but then includes a long, generic data accuracy contract that is verbose and largely irrelevant to finding FFL dealers (e.g., 'frequency, ROAS, CPA, revenue'). This distracts from the core function and wastes tokens. A concise 2-3 sentence description would be far more effective.

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?

The tool has no output schema, so the description should explain what the tool returns (e.g., dealer names, addresses, distance). It does not. It only says 'treat only fields returned by the tool as verified' without listing typical result fields. Also, radius_miles behavior and error handling are unaddressed, leaving the agent underinformed about the response.

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 has 50% description coverage: zip_code is described, but radius_miles has no schema description. The tool description does not compensate; it never mentions radius_miles, its default of 25, or how it affects results. The only parameter info in the description is 'ZIP code,' which already appears in the schema, so no additional meaning is added.

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 tool's function: 'Find Federal Firearms Licensee (FFL) dealers near a buyer ZIP code.' It uses a specific verb and resource, and distinguishes itself from sibling tools like list_gunbroker_items or search_gunbroker_items by focusing on dealer location rather than inventory or orders.

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 provides a clear use case: 'Useful for directing buyers to a local transfer dealer.' This gives context for when to invoke the tool. However, it does not explicitly mention when not to use it or name alternative tools, so it stops short of a full when/when-not guidance.

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