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

The description goes well beyond the readOnlyHint annotation by explaining that the tool always applies a date window, warns that without a filter it returns 9,800+ records, details the paging limitation that shrinking the window drops oldest records, and clarifies CPSC jurisdiction. This is rich behavioral context that prevents misuse and sets accurate expectations. No contradiction with 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?

The description is front-loaded with the core purpose, then usage guidance, then the crucial date-window and paging caveats, and finally jurisdiction. Every sentence carries essential information—no filler or redundancy. The structure guides the agent from what the tool does to how to use it safely.

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?

The description covers all operational aspects for correct invocation: ordering, date window behavior, paging caveats, and jurisdiction boundaries. The output schema is present, so return format is covered. An agent can confidently call this tool without missing critical constraints.

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% with detailed descriptions for all three parameters. The description adds critical semantic context: the consequence of not filtering (all 9,800+ records) and the subtle paging behavior that narrowing the days window cannot advance pages. This goes beyond the schema's static definitions, though the schema already documents offset behavior.

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 states the verb 'Fetch', the resource 'most recent CPSC consumer product recalls', and the ordering 'newest-first'. It clearly distinguishes this tool as a recency-focused listing, which is distinct from fetching a specific recall or searching. The purpose is unambiguous and immediately actionable.

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 explicitly says to use it for 'what's been recalled lately?' or a product safety feed, providing clear context for when to choose this tool. It does not name sibling tools or mention when not to use it, but the guidance is direct enough for an agent to correctly identify this as the go-to for recent recalls.

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