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

Annotations only supply destructiveHint=true; the description usefully adds the downstream consequence ('Auto-scheduling then skips them') and the accepted recurrence format, which the annotations cannot convey. However it says nothing about permissions, whether an existing overlapping block is replaced, or reversibility, so it leaves gaps for a mutation 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?

Three tight sentences, front-loaded with the core action and effect, with the recurrence detail and API path trailing. The 'Deputy: POST /api/v1/supervise/unavail.' line is arguably extraneous for an agent but is short and non-disruptive.

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 5-parameter mutation with no output schema, the description covers what is recorded, the one-off/recurring split, and the scheduling side effect, which is enough to call it correctly. It is somewhat thin on failure modes and permissions, but the destructive annotation plus rich schema carry most of the load.

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 start_time, end_time, recurrence, and employee_id are already documented with format guidance. The description reinforces the recurrence syntax with a concrete 'FREQ WEEKLY, INTERVAL 1, BYDAY MO' example but adds little beyond the schema's own field descriptions. 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?

States a specific verb and resource ('Record a time an employee cannot work') and immediately distinguishes one-off from recurring with an RFC 5545 example. An agent can separate this write tool from the get-side sibling deputy_get_employee_unavailability without opening either 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?

The description implies context by contrasting one-off vs recurring blocks and noting that auto-scheduling then skips the employee, but it never states when to prefer this over siblings like deputy_create_leave_request or deputy_update_shift, nor any prerequisites. Usage is inferable but not explicit.

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