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

Beyond the annotations (destructiveHint=true, idempotentHint=true), it discloses genuine behavioral traits: patch semantics ('Only the fields given change'), the status-based refusal rule, the reopen path, and that the result echoes prior values so the edit can be undone. This is unusually rich disclosure for a mutation tool.

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?

Dense but front-loaded, leading with what changes and the partial-update rule before the edge cases. The trailing example ('make Tuesday's RISE entry 3 hours') is slightly extraneous but useful for routing and does not bloat the text.

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?

An output schema exists so return structure need not be described, and the description nonetheless covers the refusal/undo behavior that matters for a mutation. Nothing an agent needs to call 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?

With 100% schema coverage the baseline is 3, but the description adds real meaning: project may be given by projectId, code or name, and it clarifies the field set that can be edited. It reinforces rather than merely repeats 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 (changes/updates) on a specific resource (the signed-in person's own time entry) and enumerates the mutable fields, so an agent can tell it apart from delete_time_entry, restore_time_entry, and log_time_entry without opening a sibling 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 clear conditions for failure: entries filed for approval, approved or invoiced are refused with a reason, and recalling the filed week reopens it. It stops short of naming the sibling tool (recall_timesheet) that performs the reopen, leaving that inference to the agent, so it is strong but not fully explicit about alternatives.

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