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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely new behavioral context: the tool can return an indeterminate result and the agent must not fabricate a price, plus the scope of the quote ('all-inclusive charter fee'). It does not mention permissions or whether the returned estimate is binding.

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, no filler, with the core action first and the fallback rule second. Every clause carries actionable content.

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?

There is no output schema, so the description is the only source of return-value information; it references the fields priced and refer_to_owner without describing the rest of the quote payload (fee breakdown, validity, currency). Given a nested-object input and unbounded output, more disclosure about the response shape would help.

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%, including the optional nested requester object, so the schema carries the parameter burden. The description adds no additional meaning about guests, nights, start, or how requester fields influence pricing, which is the expected baseline when the schema is complete.

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?

Names a specific verb and resource ('Estimate the all-inclusive charter fee from the published rate rules'), which tells the agent exactly what is computed and from what source. It also distinguishes itself from the sibling ask_owner by naming the condition that routes there instead.

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?

Explicitly states a when-not case (priced=false and refer_to_owner=true) and the correct alternative (offer to pass the question to the owner with ask_owner). It does not address other siblings like check_availability or suggest_other_yachts, but the primary routing decision is covered.

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