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

Annotations already establish that this is a non-read-only, non-destructive, open-world operation. The description adds genuinely useful behavior: the result is conditional on the trainer's "changes apply immediately" setting, and the student is notified — information the agent cannot get from the schema or annotations. Permissions and failure modes are not covered.

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?

A single dense sentence that front-loads the action and then explains the conditional outcome; no filler. The phrase "like in the app" is slightly informal but earns its place by anchoring the mental model.

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, the description covers the key behavioral ambiguity (immediate move vs pending student acceptance) and the side effect (notification), which is what an agent most needs. It does not say what the call returns or whether a pending request id can be retrieved afterwards.

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 75%, with appointment_id, proposed_date_time (ISO 8601, -03:00) and reason already documented in the schema. The description mentions the new time only implicitly and says nothing about proposed_duration_minutes, so it adds no meaning beyond the structured fields; baseline 3 applies.

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?

"Proposes a new time for a class" gives a concrete verb and resource, and the caveat that the class may move at once clarifies the actual effect better than the tool name alone. It does not name siblings like schedule_class or cancel_class, so the agent must infer the boundary from names rather than the description.

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 explains the downstream flow (student accepts, or auto-applies) which implies when the tool is appropriate, but it never states a when-to-use rule or contrasts with accept_class_change / reject_class_change / schedule_class. Usage is left to inference.

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