fda_count

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

Annotations already declare readOnlyHint=true, so no need to restate safety. The description adds valuable behavioral context: it returns 'top terms with counts' and explains the critical '.exact' suffix behavior (word splitting vs full phrase counts), which is essential for correct use. It also lists all supported endpoints, giving a full picture of the tool's coverage.

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 well-organized with a brief summary, an IMPORTANT note, an endpoints list, and per-endpoint examples. Although longer than typical, every section is purposeful and improves usability without unnecessary fluff.

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 description fully covers the tool's scope (all endpoints), return shape (top terms with counts), and critical usage nuances ('.exact'). The input schema covers parameter details, so the description completes the mental model without needing to repeat schema fields. No output schema exists, but the return description is adequate for this tool.

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% (each parameter has a description), so baseline is 3. The description adds extra value by providing concrete count_field examples per endpoint (e.g., 'pharm_class.exact' for drug/ndc) and explaining the '.exact' convention in more detail than the schema's one-line hint.

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 uses a specific verb ('Count/aggregate') and identifies the exact resource ('any OpenFDA endpoint by a specific field'), which clearly distinguishes it from the many endpoint-specific sibling tools. The statement 'Works on ALL FDA endpoints' further sharpens the scope.

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 explains when to use this tool (for counting/aggregating across any FDA endpoint) and provides critical usage details like the '.exact' suffix requirement and per-endpoint count_field examples. It doesn't explicitly mention alternatives or exclusions, but the 'Works on ALL FDA endpoints' phrasing and the comprehensive examples make the intended usage clear.

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