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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the description's added value is the authorization requirement (owner/admin only) and the status precondition, neither of which appears in structured fields. It does not say whether the rejection can be undone or whether the submitter is notified, but nothing contradicts the annotations.

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 front-loaded sentence carrying verb, resource, key parameter source and permission gate with no filler. Every clause earns its place.

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 two-parameter mutation with no output schema, the definition covers precondition, authorization and id provenance; annotations cover the safety profile. Only the post-rejection state and effect on the submitter are left unstated, a minor gap.

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 required timesheetId and optional notes are already documented. The description adds provenance for the id (it appears in the time tracking summary), which is meaning beyond the schema's 'ID of the timesheet to reject'.

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?

A concrete verb-plus-resource statement ('Rejects a submitted timesheet by its id') that an agent can distinguish from approveTimesheet by the verb alone. It does not name the sibling explicitly, so it stops just short of full differentiation.

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?

Supplies the key preconditions: the timesheet must be 'submitted' and the caller must be owner/admin. It also points to where the id comes from ('time tracking summary'). It lacks an explicit when-not or a pointer to an alternative flow (e.g. approving, or re-opening a rejected sheet).

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