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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so this is clearly a safe read operation. The description adds behavioral context by listing exactly what kind of guidance the tool provides and clarifying its role as a pre-recommendation lookup. 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?

Two short, information-dense sentences. The first lists the content domains returned, and the second gives clear usage timing. Every sentence contributes value with no repetition of schema or annotation details.

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 single-parameter read-only lookup tool, the description is complete: it states what data is returned, where the input comes from, and when the tool should be used. The absence of an output schema is compensated by the explicit list of returned content areas.

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 fully documents the single required parameter 'slug' with a description explaining it comes from search_species and giving an example. The tool description adds no new meaning beyond referring to 'a specific fish,' so the baseline of 3 is appropriate since the schema already carries the semantic load.

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 the tool returns detailed species information: habitat, diet, effective techniques, baits, and fishing regions. It identifies the resource (a species guide) and differentiates it from search_species by positioning it as the detailed follow-up lookup.

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 this tool before recommending equipment or locations for a specific fish. It also references that the slug comes from search_species, establishing a dependency. It does not explicitly contrast with sibling tools like get_lures_for_species or get_technique, but the primary use case is clear.

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