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

Annotations already declare readOnlyHint and idempotentHint, which cover mutability. The description adds value by specifying the exact return fields (proprietary name, active ingredients, dosage form, route, marketing information), which is beyond what the input schema provides. No contradictions with 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 is concise and front-loaded: the first sentence states the core purpose, the second lists return fields, and the third names related tools. Every sentence contributes meaningful information with no repetition or filler.

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 covers the essential aspects: what is searched, by which fields, and what is returned. It also points to related tools. With no output schema, it does not describe the response structure, but the listed return fields and the input schema's pagination parameters provide adequate context for typical use.

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 input schema has 100% description coverage, so the description adds little beyond what the schema already states. It lists the search fields (brand/proprietary name, application number, package NDC) but does not provide additional format or syntax details beyond the schema's own parameter descriptions.

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: searching the NSDE database by brand/proprietary name, application number, or package NDC. It names the resource (NSDE database), the search fields, and lists the return fields (proprietary name, active ingredients, dosage form, route, marketing info). It also distinguishes itself from related tools by naming them and their purposes.

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 mentions related tools (fda_search_ndc for NDC directory, fda_search_drugs for Drugs@FDA application data), giving clear context that these are alternatives. However, it does not provide explicit criteria for when to choose this tool over those alternatives, so it lacks the 'when-not-to-use' specificity required for a 5.

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