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

Annotations declare readOnlyHint=true and idempotentHint=true, so safety and repeatability are covered. The description adds valuable context beyond annotations: it specifies the confidence levels (exact, strong, possible), distinguishes recalls from signals, and describes the receipt behavior including its 400-day storage and that it is not a safety certification — a nuance not captured by annotations.

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?

Front-loads the core question, then efficiently lists accepted inputs and describes return formats. The second sentence is long but information-dense; no redundant fluff. The only slight issue is the parenthetical listing of many agencies/sources which could be abbreviated, but it serves clarity.

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?

No output schema is present, and the description fully explains what is returned: matching recalls with confidence levels, reasons, agency source links, plus early-warning signals with their sources. It also covers the receipt parameter's behavior. Given 7 parameters (all optional), the description adequately guides the agent on what inputs are accepted and what to expect, leaving no critical gaps.

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 baseline is 3. The description adds meaning beyond the schema by listing the acceptable identifier types and implying they can be combined ('Give whatever you have'), which clarifies that not all parameters are required and that partial data is acceptable. It doesn't add format details beyond the schema, so not a 5.

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?

States a specific question ('Is this product recalled?') and names the exact resource (product recalls) and scope (9 US agencies + 5 early-warning sources). Sibling tools (check_vehicle, get_recall, search_recalls) are clearly differentiated: this is a lookup by identifiers, not a search or vehicle-specific check.

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?

Makes clear this is for product recall checking and what inputs are acceptable ('Give whatever you have'), which implies when to use it. However, it does not explicitly contrast with alternatives like search_recalls or get_recall, nor does it state when not to use it (e.g., for vehicles, the sibling check_vehicle exists).

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