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

Goes well beyond the annotations (readOnlyHint=false, openWorldHint=true, destructiveHint=false). It discloses the return values (booking_id and folder), the confirm-each-call default and the ability to disable it, the requirement to confirm with the user before calls, and the Cotlet API key/app-access requirement. This is rich, actionable behavioral context for a mutating open-world tool.

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 core action and scenario logic, and every sentence is relevant. It is slightly padded by restating the title in the opening phrase and by two overlapping confirmation statements, but there is no real waste.

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 fills that gap by naming the returned values. Combined with the annotation-supplied safety profile, full parameter coverage, and the auth/confirmation context, an agent has everything needed to call this 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 coverage is 100%, so the schema already documents every parameter including the enum values for payment and save_as. The description largely restates these (name+email for new customers, provider omission → unassigned, save_as alternatives) and adds no new syntax or format guidance, so the baseline of 3 is appropriate.

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+resource (create a booking) and immediately distinguishes the scenarios: existing vs new customer, with or without a provider. An agent can tell it apart from bookingkoala_get_booking, list_bookings, cancel_booking, reschedule_booking, and send_quote without opening any 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?

Explains when each mode applies: pass a name/email for a new customer, omit provider_id to leave it unassigned, and use save_as to store a draft or quote instead of a booking. It gives clear context but does not name a sibling tool (e.g. send_quote) for the quote path, so routing is implicit rather than explicit.

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