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

readOnlyHint=true already covers the safety profile, so the bar is lower, and the description adds real value by disclosing that the payload contains breaks and approval state — meaningful context given there is no output schema. It also cites the underlying endpoint, aiding traceability. No pagination or error behavior is mentioned, but that is not expected for a single-record read.

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?

Two short sentences, front-loaded with the action and payload, followed by an endpoint reference. Nothing is redundant and nothing needs re-reading.

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 single-parameter read with annotations covering safety and no output schema, this is nearly sufficient: it says what is returned (breaks, approval state) and where it comes from. A brief note on how this differs from the list/update tools would close the remaining 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?

With one parameter at 100% schema description coverage, the schema already documents timesheet_id; the description adds no format, range, or sourcing guidance beyond the '{id}' placeholder in the endpoint string. This is the baseline 3 case where structured fields do the heavy lifting.

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 (fetch) and resource (one timesheet) with a scope qualifier ('one') that implicitly distinguishes it from deputy_list_timesheets. However, it never names the sibling tools it must be told apart from, so differentiation is left to inference.

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?

Usage is only implied: the agent is expected to infer that this is the right call when it has a specific timesheet_id and needs the detailed record. There is no explicit when-to-use, no exclusion of the list/update/approve siblings, and no stated prerequisites.

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