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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. Beyond that, the description adds that results are paginated and include starting price and rating — useful return-shape context given there is no output schema — though it omits ordering of results, whether matches are fuzzy, and any rate-limit or result-cap 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 tightly written sentences with the capability front-loaded and return shape second. There is slight redundancy between 'with sorting and pagination' and 'Returns a paginated list', but no filler.

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?

With four parameters, 0% schema coverage, no output schema, and a non-trivial domain (bookable charters), the description is only minimally sufficient. It covers the filter dimension and hints at returned fields, but leaves sort semantics, pagination limits, and the distinction from get_captain/search_boats for the agent to guess.

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 for four undocumented parameters. It does name the harbor filter, sorting, and pagination conceptually, but adds no detail on sort options (rating, price_asc, price_desc, name), defaults (page=1, limit=20), or the limit cap of 50 that the schema enforces — so meaning beyond the schema is thin.

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 verb and resource ('Search bookable charter captains') plus scope qualifiers (harbor filter, sorting, pagination), which clearly separates it from siblings like search_boats and get_captain by resource type. It stops short of explicitly naming those siblings, so differentiation relies on the agent inferring from the noun.

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 phrase 'optionally filtered by harbor' implies the intended browsing use case and that no filter is required, but there is no explicit when-to-use/when-not guidance and no mention of alternatives such as get_captain for retrieving a single captain. Usage is inferable rather than stated.

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