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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the description correctly spends its space elsewhere: data provenance (openFDA product classification database), the US-only coverage boundary, the caveat that exemptions can carry regulatory limitations, and the 1-credit cost. That is meaningful context an agent cannot get from the annotations, though it does not discuss result volume or what an empty result means.

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 return payload is front-loaded, then scope limits, then caveats and cost — a sensible order with no filler sentences. Slightly padded by the audience enumeration ("start-ups, importers and consultants"), which adds framing but little operational value.

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 compensates by listing every returned field, so the agent knows what it will receive before calling. Combined with source, jurisdiction limit, caveat and cost, nothing material is missing for a read-only lookup 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 states its format, the code-vs-device requirement, and the 1-20 limit range. The description adds no further guidance on parameter choice (e.g. preferring a code for precision over a free-text device name), so it sits at the baseline where the schema does the work.

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?

Opens with a specific verb+resource ("Returns the FDA classification for a type of medical device") and enumerates exactly what comes back: risk class, product code, regulation number, specialty, definition, premarket route, implant/life-sustaining flags. It is clearly distinguishable from siblings like fda_device_510k_clearances or fda_device_pma_approvals, which cover the downstream clearance records rather than the classification itself.

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?

Gives concrete use cases ("what class is my device?", "do I need a 510(k)?") tied to named audiences, which tells the agent the triggering intent. It also supplies a when-not constraint via jurisdiction ("US classification only; it does not cover UK/EU (UKCA/CE) classes"). It never explicitly names the sibling tools to use for clearance/approval histories, which keeps it short of a 5.

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