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

The annotations already declare write, non-destructive, idempotent, closed-world behavior, so the bar is lower; the description adds the outcome (a stamp and the treasure-hunter badge) and discloses that the visitor name is public CC0 with no personal data. It does not say what an incorrect or duplicate submission does (rejection message, partial credit), which is the main remaining gap.

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 front-loaded sentences with no filler: the requirement comes first, the reward second, the privacy disclosure last. Dense but every clause carries a rule; minor cost is that the acceptance rules are packed into one long sentence.

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?

For a two-parameter submission tool with no output schema, the description supplies requirements, the success outcome, and the data-visibility disclosure. The missing piece is error behavior on an invalid hunt, which an agent attempting a retry would want.

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 baseline is 3. The description does add a constraint the schema cannot express — the 3 tokens must come from 3 different collections and from a query containing today's theme — which is genuine meaning beyond minItems: 3, but visitor_name is only covered by the schema text.

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 names a specific verb and resource ("Hand in today's treasure hunt") and enumerates the acceptance rule (ficha_caza tokens from at least 3 results across 3 different collections). It never names the natural companion tool todays_hunt or the search tools that produce tokens, so sibling differentiation is implied rather than stated.

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?

It clearly scopes when to call it: only after collecting qualifying tokens from a theme-matching query. It does not explicitly tell the agent to call todays_hunt first for the theme or point to search_pieces/search_open_collections as the token source, and no failure/exclusion paths are stated.

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