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

Annotations already carry the safety profile (readOnly, idempotent, openWorld, non-destructive), so the description adds genuinely new behavior: a $0.01 USDC per-call cost via x402 on Solana, the HTTPS fallback endpoint, and default ordering. It does not state pagination limits in prose (they are in schema), which keeps it from a 5.

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?

Dense but front-loaded: what it is, what it returns, how to filter, then cost and alternate endpoint. Every clause carries information; the parenthetical field list is slightly packed but not wasteful.

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?

For a 15-parameter, fully-documented, read-only search tool with no output schema, the description covers source scope, defaults, and cost — enough for an agent to call it correctly. Return shape is unspecified but the field list partially compensates.

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 the schema already documents all 15 parameters including enum values and range hints. The description reinforces a few semantics (count by any field, newest-first default sort, source=recall device-only) but adds little beyond the schema; 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?

The description opens with a specific resource and source (FDA recalls via openFDA enforcement reports for drug/device/food) plus the device recall database, and lists the fields returned. It is clearly distinguishable from fda_adverse_events, though it never names a sibling directly (fda_device overlap on device recalls is only implied via source=recall).

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 enumerates the filtering capabilities (firm, product, class, status, state, dates) and defaults (source enforcement, category drug, newest first), which implies how to drive the tool. But there is no explicit when-to-use vs when-not guidance, and no routing to siblings like fda_device or fda_adverse_events.

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