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

Annotations only declare the safety profile (readOnly=false, destructive=false, idempotent=false); the description goes well beyond that by describing the full domain outcome — advance-notice types refuse earlier starts and return the earliest valid date, no-approval types are granted immediately, otherwise approvers are notified. It also discloses day-counting semantics against the working week and holidays, and that requestKey files at most one request.

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 purpose and required fields are front-loaded, followed by workspace-rule behavior and identity constraints, with the natural-language examples placed last where they aid slot-filling. It is dense but nearly every clause carries operational meaning; the closing example sentence is the only part that could be trimmed.

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 7-parameter mutation tool, the description covers identity constraints, date-range scoping, day counting, approval-flow outcomes, and per-request deduplication. With an output schema present, return values need not be explained, so nothing an agent needs to invoke this correctly is missing.

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 schema already documents all seven parameters and the baseline is 3. The description reiterates key semantics (days, requestKey dedup, userId refusal) and slightly enriches 'days' by tying it to the working week and holidays, but adds little syntax or meaning the schema does not already carry.

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?

The description names a specific verb and resource ('Asks for time off for the signed-in person'), scopes it with the exact fields (startDate to endDate inclusive, one of the workspace's leave types), and makes clear it acts on behalf of the signed-in user rather than an arbitrary one. An agent can distinguish this from list_my_time_off, withdraw_time_off, or restore_time_off without opening any 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?

It gives clear triggering context, including example utterances ('take Friday off', 'request vacation the week of the 24th') and the rule that userId is unnecessary when signed in because other IDs are refused. It does not explicitly route the agent away from sibling tools such as withdraw_time_off or list_pto_requests, so exclusions are left implicit.

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