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

Annotations only supply destructiveHint=true; the description adds real behavioral context beyond that: it is a mutation that writes to the connected EHR/PMS, and it can optionally notify the patient — a side effect an agent should know about before invoking. It stops short of covering permissions, idempotency, or error behavior, but the added value over annotations is genuine.

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?

Four short clauses, front-loaded with the verb and the mutation warning, then the constraint, then the endpoint. No filler sentences and each clause carries actionable 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 write tool with no output schema, the description covers purpose, side effects, and the key parameter constraint. It would be stronger if it indicated what is returned (e.g., the created appointment id) or failure modes, but the essential booking information is present.

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 the baseline is 3. The description goes beyond the schema by stating the cross-parameter constraint that end_time and appointment_type_id are alternatives, and by flagging the optional patient-notification side effect, which the schema only partially conveys.

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 ('BOOK a new appointment'), names the target system ('creates an appointment in the connected EHR/PMS'), and includes the underlying endpoint. This clearly distinguishes it from nexhealth_update_appointment, nexhealth_get_appointment, and nexhealth_list_appointments.

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?

The description gives one useful invocation rule ('Provide either end_time or appointment_type_id'), which steers how to call it. However, it never says when to choose this tool over siblings such as nexhealth_update_appointment, nor does it mention prerequisites like needing to resolve location/provider/patient ids first. Usage is implied rather than explicitly framed.

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