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

With no annotations, the description carries the behavioral burden and does well: it discloses fresh unseen images, instant scoring, full answer-key return, leaderboard visibility, and a daily entry limit. It does not cover error behavior or what happens if answers are incomplete.

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 task, then branches into 'Without answers' and 'With answers' behavior. It is dense and informative, with only minor verbosity from stacked parentheticals.

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 tool with no annotations and no output schema, the description provides strong context: purpose, both modes, scoring behavior, entry limit, and ground truth. It could more fully specify the return format and edge cases, but it is largely complete.

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 0%, so the description must compensate. It explains that `answers` should be six values of 'same' or 'different' and that `name` is needed for scoring, adding useful semantics beyond the bare schema, though it does not explain maxLength or extra-answer handling.

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 activity and resource: a daily wildlife re-identification test on wild trout using six underwater photo pairs, with a same/different task. It is clear what the tool does, though it does not explicitly differentiate itself from the many sibling trout-themed tools.

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 clearly explains two usage modes: calling without answers returns today's pairs, tips, and leaderboard; calling with six answers and a name returns an instant score. It also states the one-entry-per-player-per-day constraint, though it does not reference sibling alternatives.

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