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

Annotations already declare readOnlyHint=true and destructiveHint=false, so 'It is read only and cannot be edited' largely repeats structured data. It does add genuinely useful context beyond annotations: the 'booked via' source explanation and the Cotlet API key access requirement.

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?

The returned-field list is stated twice ('customer, service, team member, start and end, label and where it was booked' then again 'with the customer, service, team member, start and end, and its label'), wasting the opening without adding 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?

For a single-parameter read tool with no output schema, the description covers the returned fields, the auth requirement, and the meaning of 'booked via.' Adequate for correct invocation, with only the redundancy and missing sibling routing as mild gaps.

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 parameter is documented in the schema as 'Appointment ID from list_appointments.' The description adds no additional syntax or format detail for the ID, so baseline 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 ('Returns one appointment') and enumerates the returned fields (customer, service, team member, times, label). 'One appointment' implicitly distinguishes it from the sibling list_appointments, but the description never names that sibling to make the contrast explicit.

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?

No guidance on when to use this vs setmore_list_appointments or the other appointment tools. The only routing hint ('Appointment ID from list_appointments') lives in the schema's parameter description, not the tool description.

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