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

Annotations already declare readOnly/non-destructive/closed-world, but the description adds real behavior: it returns ONLY active discounts (a filter), documents the empty-list meaning, and describes the return shape (value, booking/stay windows, covered boats). It stops short of noting anything about volume, pagination, or permissions, but it meaningfully exceeds what the annotations convey.

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, densely front-loaded: the resource and its contents come first, the empty-list edge case last. The parenthetical field notation (start_date..end_date, all_boats/boat_ids) is compact and every clause carries 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 carries the burden of describing return values and does so thoroughly, including the two date windows and the boat-coverage fields. Only minor gaps remain — no mention of pagination or ordering of the returned list.

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 coverage is 100% and the single company_id parameter already documents its source (list_boats or get_company). The description references 'the company's' discounts but adds no extra semantics about the identifier, so baseline 3 applies.

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 names a specific resource (the company's active discounts) and enumerates exactly what the result contains — promo codes, automatic discounts, pay-in-full discount — so an agent knows precisely what it will get back. It does not explicitly contrast itself with siblings like get_pricing or create_discount, but the read-only listing intent is unambiguous.

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?

Usage is implied rather than stated: the word 'active' signals that expired/inactive discounts are excluded, and 'An empty list means the company runs no discount' tells the agent how to interpret a null result. There is no explicit when-to-use-vs-alternative guidance and no stated prerequisite beyond supplying a company_id.

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