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

Annotations only declare destructive/openWorld/non-idempotent; the description goes far beyond by disclosing the manager e-mail side effect, the exact semantics of the auto-approve path, the date-window and cycle restrictions, and that the action 'Cannot be undone through this server' — consistent with destructiveHint=true. This is the side-effect detail an agent needs before a mutation.

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?

Front-loaded with the write action and the highest-stakes branch (manager e-mail) first; every sentence carries information. It is dense to the point of run-on in the preapproved sentence, which slightly slows parsing, but nothing is wasted.

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?

A destructive 7-parameter mutation with no output schema, and the description covers side effects, constraints, and the key optional parameter's fallback. It stops short of saying what comes back (e.g., whether a request id or pending state is returned), which forces the agent to infer the success signal.

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%, so baseline is 3, but the description adds real meaning: the per-day value convention (1, 0.5, 0 for non-working days) and, crucially, that TalentHR computes amounts when amount_options is omitted — behavior absent from the schema. preapproved's 'allowed to' caveat also adds nuance beyond the schema text.

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?

Opens with an explicit verb+resource pair ('WRITE: book a time off request for an employee') and immediately distinguishes the operation from sibling reads (list_time_off_requests) and the related reply_time_off_request. An agent can route to it without opening the 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?

Gives explicit when-to-use conditions for the ambiguous parameter ('only use it when the user explicitly said the time off is already approved'), names the sibling that supplies the type id (talenthr_list_time_off_types), and states hard eligibility constraints (within one year, inside a time off cycle). No inference required.

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