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

No annotations are provided, so the description carries the full behavioral burden. It discloses the returned content—names, photos, species guess, habits, favorite times, recent sightings, current frame status, and population—but does not explicitly state that the operation is read-only, nor does it discuss permissions, limits, or error behavior.

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?

Two sentences, front-loaded with the roster purpose and followed by the optional single-profile use case. The field list is dense but earns its place by telling the agent what returns.

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 simple, one-parameter, read-oriented tool with no output schema, the description covers both modes and enumerates the returned content. It could be stronger by clarifying the default no-slug result and invalid-slug behavior, 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?

The schema has one optional parameter, fish, with 0% description coverage. The description adds useful meaning by explaining that the value is a fish slug that selects a single profile, but it does not specify slug format, lookup behavior, or what happens if the slug is unknown.

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 the resource clearly—individual wild trout in the pool—and states both roster and single-profile behavior. It is specific about the fields returned, though it does not explicitly differentiate itself from siblings such as trout_now or whos_that_trout.

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 explains the two modes: omit the slug for the pool roster, or pass a fish's slug for one profile with sightings. It does not name alternatives or when-not-to-use cases, but the usage context is clear.

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