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

With no annotations, the description carries the burden and does real work: it discloses the state machine (a rejected entry returns to 'waiting for approval', approved entries are immutable except via owner reopen). It does not clarify whether this is a partial patch or a full replace, or what permissions are required, which is the remaining gap for an unannotated 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?

Three short sentences, front-loaded with the purpose and least-privilege precondition, followed by the state-transition note and the two alternative routes. No filler.

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 values need not be explained, and the description covers the tool's key behavioral constraints (unapproved-only, state transitions, locked approvals). Missing only patch-vs-replace semantics and permission details for a mutation tool with zero annotations.

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 only 14% (only 'category' is documented), so the description must compensate. It does name the editable fields, mapping loosely onto the seven parameters, but adds no format, null-handling (job_id and visit_id are nullable), or partial-update semantics. Helpful but not enough to fully offset the coverage gap.

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 gives a specific verb and resource ('Fix a time entry'), enumerates the editable fields (start, end, category, job, visit, notes), and scopes it to entries 'that are not approved'. It also names the two nearest siblings (timesheets.clockOut, timesheets.reopen) so the agent can tell the tools apart immediately.

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?

Explicit exclusions are stated: a running clock's end goes through timesheets.clockOut, and approved time is locked and must be reopened by the owner via timesheets.reopen. The precondition (entry must be unapproved) is stated up front rather than left to inference.

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