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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: it enumerates the return payload (16 CFR citation, whether a CPSC-accepted lab must test, eFiling citation code) and states the coverage boundary (16 common children's types plus 3 general) and a negative capability (does not rule on legality).

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?

Purpose and the CPC/GCC distinction are front-loaded, followed by input guidance, scope, return shape, and a caveat. Every sentence carries information, though the density is high and it runs a bit long relative to a 3-parameter tool.

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?

An output schema exists so return values needn't be explained, yet the description still summarizes the payload helpfully. Combined with explicit input guidance, scope limits, a sibling hand-off, and a stated limitation, an agent has everything needed to call it correctly and interpret results.

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?

With 100% schema description coverage the baseline is 3, but the description adds practical meaning: it clarifies that 'product' may be free text or a description of what a photo shows, and tells the agent to add age and features 'when known,' enumerating feature examples (paint, small parts, batteries, magnets, metal parts) that map to the enum. This is useful guidance layered on top of the schema rather than a restatement.

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) and resource (US product-safety rules and the certificate the importer files), and distinguishes the two certificate types CPC vs GCC with a parenthetical. An agent can tell what it produces without opening the schema, and it clearly differs from siblings like find_accepted_labs and match_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?

It gives explicit invocation guidance (pass product as plain words or describe a photo, add age and features when known) and routes the agent onward via 'Use testedRuleIds with find_accepted_labs.' It also scopes out a tempting misuse with 'It does not decide that a product is legal to sell,' though it doesn't state when a sibling tool would be preferred instead.

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