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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context the annotations do not: cost model (free within daily allowance, then $0.003 USDC per call via x402). It says nothing about result volume, pagination, or rate limits beyond the allowance.

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?

Two short sentences, resource identified first, pricing second; every word carries information and nothing is padded. It is arguably under-specified rather than over-long, but for the conciseness dimension itself the structure is tight.

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 need not be explained, and the schema covers both parameters. However, for a search-driven endpoint the description omits how to actually query it and any distinction from sibling endpoints, leaving the agent to infer usage entirely from the schema.

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%, so both parameters (search, limit) are already documented in the schema, establishing the baseline of 3. The description adds no syntax or format guidance for the openFDA search expression, so it does not exceed the baseline.

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 names the specific resource (medical device recalls), which cleanly separates it from siblings like openfda__device-events, openfda__device-510k, and openfda__drug-recalls. It lacks an explicit verb (search/list/retrieve), but the noun phrase plus the sibling set makes 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?

There is no when-to-use guidance, no mention that a search expression is required, and no routing advice versus the other openFDA endpoints. The only conditional text concerns billing, not invocation context.

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