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

Annotations only cover readOnlyHint=false, destructiveHint=false, and openWorldHint=true; the description adds substantial behavioral context beyond them: the channel/booking-engine availability drop, the red Calendar display, that the end date is inclusive, that it does not relocate existing bookings, and the default per-call confirmation. It also discloses the auth requirement (Cotlet API key) and the external-impact warning ('Reaches other people: confirm with the user before each call'), which is exactly the kind of context annotations cannot 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?

It is front-loaded and readable, but the availability/channel consequence is stated twice in near-identical wording ('availability sent to channels and the booking engine drops' ... 'Availability sent to channels and your booking engine drops'), so one sentence does not fully earn its place. The remaining sentences are informative but the duplication costs conciseness.

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?

For a mutation tool with no output schema and an openWorld hint, the description covers everything needed to call it correctly: scope of effect, inclusive date semantics, non-effect on existing bookings, default confirmation behavior, external-recipient warning, and the required API key. Nothing material is missing.

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 all four parameters are already documented, including 'Last date of the range, inclusive.' The description's 'The end date is included' merely restates that inclusive-boundary fact rather than adding syntax, constraints, or ID semantics beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 ('Closes rooms or whole room types for a date range') and ties it to a concrete UI counterpart ('like Room Closure on the Front Desk Calendar'). It also pre-empts confusion with the nearest sibling concept by stating 'A closure is not a stop sell,' so an agent can distinguish it from update_restrictions without opening either schema.

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 usage context: this is for blocking availability over an inclusive date range, and by default each call is confirmed. It also distinguishes closure from stop-sell, which functions as an implicit alternative. However, it never names the sibling tool (e.g. update_restrictions) an agent should reach for when a stop sell is actually intended, so routing is left partly to inference.

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