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

Annotations already declare readOnly/idempotent/non-destructive, but the description goes well beyond them: it discloses per-call cost, the no-charge conditions (no match or stale data), a hard cap of 10 rows, the absence of remedy text, and that results carry data dates plus an FDA address. These are exactly the traits an agent cannot infer from structured fields.

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?

Cost and scope are correctly front-loaded in the first clause, and the sentences carry real information about output limits and omissions. The enumeration of faceted filters partially repeats what the schema already lists, which is the only waste.

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?

With no output schema, the description must describe returns and it does (up to 10 recall rows, dates, FDA address, no remedy text). It leaves open whether 10 is a hard ceiling with no pagination path and never states the consequence of calling with zero filters, which is a real gap for a 6-optional-parameter 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 description coverage is 100% and each parameter already carries format, enum and matching rules, so the schema does the heavy lifting. The description's filter list mirrors the schema property names without adding matching semantics beyond it, so the baseline of 3 applies.

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?

Specific verb plus specific resource ('search the U.S. Food and Drug Administration's published enforcement reports') with a parenthetical scope of food, drug and device recalls. The retrievable facets are enumerated, and the resource is unambiguously distinguished from the sibling 'search_health_canada_recalls'.

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 parenthetical '(give a firm, a recall number, a keyword or a since date)' sets an implicit precondition that at least one narrow filter should be supplied, and the billing rules tell the agent when a call costs money. It stops short of naming a sibling alternative or an explicit 'do not use when' case, so it is clear but not fully routing-aware.

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