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

Annotations only supply the generic hint set (readOnlyHint=false, destructiveHint=false, idempotentHint=false); the description goes well beyond them by disclosing that entries lock, approvers are notified, exempt roles are auto-approved, and that refusals occur for empty or already-filed periods. Those consequences are exactly what an agent needs before invoking a non-idempotent 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 purpose, then behavior, refusals, and return value in a tight three-sentence block with no filler. The closing sentence about the result is partly redundant given an output schema exists, which is the only wasted clause.

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?

With annotations, a fully documented schema, and an output schema in place, the description covers the remaining unknowns an agent needs: locking, notification, auto-approval, refusal conditions, and which period modes are valid. Nothing material 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 coverage is 100%, so the baseline is 3, but the description adds real semantics: the week is defined as Monday-to-Sunday, weekOf defaults to this week, and periodStart/periodEnd are framed as an exact alternative period. The only gap is that userId's signed-in-vs-connection distinction is left entirely to the schema.

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 ('Files the signed-in person's timesheet for approval') and pins down scope: the signed-in person's own sheet, not someone else's. An agent can distinguish this from approve_timesheets (approver action), return_timesheet, and recall_timesheet without opening a 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 concrete selection conditions: use weekOf (defaulting to this week) or an exact periodStart/periodEnd pair, and it states when the call is refused (no entries, already filed) plus the exempt-role auto-approval case. It gestures at the recall counterpart ('the call that recalls it') but never names recall_timesheet, so the alternative is implied rather than explicit.

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