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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: the non-error edge case for digitization gaps and the content disclosed (predicate device, testing behind equivalence finding). This goes beyond repeating structured data.

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?

Three sentences with no fluff: the first front-loads the action and sibling contrast, the second explains the value-add content, and the third covers the edge case. Every sentence earns its place.

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 a rich annotation set and an output schema present, the description covers everything needed for correct invocation: what it returns, how it differs from the sibling, and the non-error edge case. Nothing critical is missing.

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 only parameter, k_number, is already fully documented in the schema with an example and an 'Exact K number' instruction (100% coverage). The description merely restates 'by K number' without adding syntax or format details, so baseline 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?

Description uses a specific verb ('Get') and names the exact resource: the FDA 510(k) summary/statement document and FDA review (decision memo) for one clearance by K number. It explicitly distinguishes this from fda_device_510k_search, making the purpose unambiguous.

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?

Explicitly names the sibling fda_device_510k_search and explains that this tool returns 'the actual filing' rather than just the 'a document exists' flag. It also sets expectations for older/paper-only clearances (returns summary_available:false with a reason), so the agent knows when this tool is appropriate and what to expect.

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