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

Annotations already establish read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds meaningful context beyond annotations by detailing the return fields (price, duration, capacity, target species, operator) and stating that charter filters apply here too, which informs the agent about inherited filtering 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?

The description is two sentences, front-loaded with the primary action and key filters/returns in the first sentence, and the second sentence clarifies the catalog relationship. Every word earns its place, with no redundancy or fluff.

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?

Given the tool's straightforward search nature, the presence of annotations, and an output schema, the description covers the essential purpose, return fields, and category context. It could be more explicit about sibling differentiation, but overall it is sufficient for an agent to understand scope and expected results.

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 description maps several parameter concepts to schema properties ('departure area' to location, 'date' to date, 'angler count' to anglers, 'technique' to charter_style), but it does not mention the limit or duration_type parameters. With schema description coverage at 67%, the description partially compensates but leaves two parameters undocumented in both schema and description.

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 opens with a specific verb and resource ('Searches fishing charter trips'), then lists distinct filter dimensions (departure area, date, angler count, technique) and return fields (price, duration, capacity, target species, operator). It also distinguishes from siblings by explicitly noting fishing trips are a category of the charter catalogue, which clearly separates it from charter_search and sailing_search.

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 implies that this is a specialized search within the charter catalogue ('Fishing trips are a category of the charter catalogue'), but it does not explicitly state when to prefer this over charter_search or sailing_search, nor does it mention any exclusions or alternatives. The usage context is only implied by the name and the category note.

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