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

Annotations already cover read-only, idempotent, open-world and non-destructive traits, so the bar is lower. The description adds real value by disclosing result ordering (newest first) and the shape of returned data (affected models, manufacture date window, defect, risk, free remedy), which the annotations do not provide.

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 tight sentences, front-loaded with the core action and scope, then usage trigger, then practical owner guidance. No filler, no repetition of the title.

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 usefully enumerates the returned fields and coverage window, and annotations handle safety semantics. Only minor gaps remain (pagination, behavior on zero matches, whether brand is required), which are not critical to correct invocation.

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 coverage is 100%, so the schema documents brand and model with examples, making 3 the baseline. The description's 'by brand and/or model' adds genuinely useful semantics: either parameter can be used alone, matching the zero-required-parameter design and the OR search logic.

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 verb and resource (search NHTSA safety recalls for child car seats/boosters), gives scope (2010 onward, sorted newest first), and is clearly distinguishable from siblings like get_vehicle_recalls and search_product_recalls by naming the child-seat domain.

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 says to use it 'when the user asks whether a car seat, infant seat or booster is recalled,' plus adds post-search guidance on comparing manufacture date and model number. It does not name a competing sibling or a when-not condition, so it stops short of the top tier.

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