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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description adds real value beyond that by enumerating the return scope: boats, partner links, and event types by source. It omits return format and pagination details, but for a read-only tool this is solid added context.

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?

Front-loaded with the tool's identity, followed by a dense enumeration and a one-line usage hint. The em-dash list is a bit heavy but each clause carries information; nothing is padding.

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 compensates by describing what the calendar contains and its event sources. Combined with the read-only annotations and 100% schema coverage for the single parameter, an agent has enough to call it correctly.

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%, and the single company_id parameter is fully documented in the schema (including where to source it). The description adds no parameter-level meaning, so the 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 states a specific resource and scope: the company's fleet calendar listing every boat with partner links and every date-consuming event (bookings, options, blocks, synced partner/iCal events) with its source. This is far more concrete than a generic 'get', though it never names itself as distinct from near-siblings like list_bookings or list_calendars.

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?

It gives explicit context: 'Read it before add_block to see what a range already holds,' tying usage to a concrete sibling and precondition. It does not state exclusions or when another listing tool is preferable, so it falls short of a full when/when-not breakdown.

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