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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and scope are covered by structured data. The description usefully adds that this is a range/season-scale query filtered by a minimum-nights threshold, but says nothing about result shape, granularity of returned windows, or how the requester block is used.

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 sentences, zero filler, with the core capability front-loaded and the usage cue second. Nothing could be removed without losing information.

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 no output schema, the description still gives an adequate picture of the query (date range plus minimum nights) and when to reach for it. The nested requester object's follow-up purpose is left entirely to the schema, which is a minor gap rather than a blocking one.

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 100%, so from/to formats, the requester object, and min_nights are already documented in the schema. The description reinforces min_nights as a filter and characterizes the range scale ('a whole month or season'), which is mild added value over the schema but not beyond the baseline.

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 ('List open windows between two dates') plus a qualifying constraint ('for charters of at least min_nights'). It is distinguishable from a point-in-time availability check, though it never names the sibling check_availability to sharpen the contrast.

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?

Gives clear situational context: 'Use when the guest is flexible or asks what's open.' That tells the agent the query shape this tool is for, but offers no exclusions or explicit routing versus check_availability or suggest_other_yachts.

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