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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive, so the safety profile is covered. The description adds valuable behavioral context: no authentication required, public domain data, unlimited free access, and the newest-first ordering with specific return fields. This goes beyond the annotation set.

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?

The description is reasonably concise, with the core purpose in the first sentence and supporting details (use cases, data access) following. It is structured with no filler, and each sentence contributes to either purpose, usage, or behavior.

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?

Given the presence of an output schema and full parameter documentation, the description adequately covers purpose, return values, and access constraints. It even mentions the lack of auth and free usage, which is useful for an agent. Nothing critical is missing for a read-only lookup tool.

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 schema already provides 100% parameter coverage with detailed descriptions and examples for days, limit, and product_type. The description adds a couple of extra examples for product_type but does not materially enhance understanding beyond the schema. Baseline 3 is appropriate since the schema does the heavy lifting.

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 clearly states a specific action: fetch recent US CPSC consumer product recalls within a given number of days. It also lists the return fields (title, affected products, hazards, remedy options, manufacturer details) and the ordering, which is distinctive. The 'recent' angle and 'within the last N days' naturally differentiate it from sibling tools like search or by_manufacturer.

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?

The description gives explicit context on when to use this tool: for safety monitoring agents, compliance dashboards, and consumer protection workflows tracking new recall announcements on a daily or weekly basis. It does not explicitly mention alternatives to avoid, but the use-case framing makes the intended scope clear.

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