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

Annotations declare readOnlyHint=false, destructiveHint=false, openWorldHint=true. The description adds genuinely non-redundant behavior: the appointment may trigger a client-facing email, it 'reaches other people', and it needs a Cotlet API key with app access. This side-effect and auth transparency is valuable, though it doesn't say what changes to the appointment record itself (e.g., billing implications).

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 core action ('mark an appointment as a no-show, before its end time') is stated twice almost verbatim, wasting space. The unique behavioral notes (email side effect, confirmation, API key) are valuable but the redundancy hurts front-loading efficiency.

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 tool with annotations covering the safety profile, the description adds the important missing pieces: the email side effect, the external-reach confirmation requirement, and auth needs. Sufficient, though it lacks any return/result outcome, which matters since no output schema exists.

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?

Only one parameter with 100% schema coverage, and the schema already documents 'Appointment ID from list_appointments.' The description adds no syntax, format, or sourcing detail beyond the schema, 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 ('mark') and resource ('appointment as a no-show') plus a timing constraint ('before its end time'). An agent can distinguish it from siblings like thryv_list_appointments or thryv_book_appointment without opening a 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?

Provides a clear usage condition ('before its end time') and the confirmation workflow ('confirm with the user before each call'), which frames when to invoke it. However, it names no sibling alternatives or exclusions (e.g., why not cancel or reschedule), so the routing guidance is contextual rather than explicit.

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