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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: winners are sorted by draw date (most recent first), supports search by email or phone, and advises using raw data internally while presenting only human-readable names, emails, and draw dates. This goes beyond the annotation hints.

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 structured with sections (title, When to use, Pre-calls, Parameters) which aids navigation, but it unnecessarily repeats the opening paragraph verbatim in the 'When to use' section. This redundancy makes it longer than needed, though the front-loaded summary does provide immediate 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?

The tool has no output schema, so the description carries the burden of explaining return-related context. It adequately covers prerequisites (fetch_sweepstakes), pagination defaults, sorting behavior, search capability, and how to present results. Given the read-only nature and modest complexity, this is sufficiently complete, though it could mention error scenarios or rate limits.

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 baseline is 3. The description includes a 'Parameters to validate before calling' section that mirrors the schema's parameter descriptions (e.g., sweepstakes_token UUID format, default values for page and items_per_page). It adds minimal new meaning beyond the schema, except framing these as validations to perform before calling, which is a minor semantic addition.

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 'Get winners from a sweepstakes with pagination', using a specific verb and resource. It further distinguishes itself from siblings like 'draw_winners' (which creates winners) and 'fetch_sweepstakes' (which retrieves sweepstakes) by focusing on retrieving existing winners. The mention of sorting by draw date adds scope specificity.

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 instructs to 'Use fetch_sweepstakes first to get the sweepstakes_token' and includes a 'Pre-calls required' section detailing the prerequisite. It also gives guidance on handling results ('Use them internally for tool chaining but present only human-readable information'). While it doesn't explicitly mention when NOT to use it or alternatives, the context is clear and actionable.

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