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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false). The description usefully adds that the result is a DRAFT (not a submitted entry) and that the feature requires PRO+, which are genuine behavioral facts beyond the annotations. It does not cover retry semantics or how the entry enters approval, so it adds some but not rich context.

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?

Four compact clauses, front-loaded with the action and output state, then constraints, then feature gating. Every sentence earns its place, though the hours/date constraints duplicate the schema rather than adding new information.

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 mutation tool with no output schema, it adequately states what is created (a draft entry) and the input preconditions. It omits what happens after creation (approval flow, returned identifier) and the permissions required, leaving some gaps for an agent to close.

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 only 50% (taskId, projectId, notes undocumented). The description restates the hours range and future-date rule that the schema already documents, and only 'within project dates' adds new meaning for `date`. It does nothing to compensate for the three undocumented parameters.

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+resource ('Log hours worked on a task') and clarifies the output state ('creates a DRAFT timesheet entry'), which meaningfully separates it from submit_timesheet or update_timesheet_entry. It does not explicitly name those siblings, so an agent must infer the workflow position.

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?

The DRAFT qualifier implies a create-then-submit workflow, and the constraints (hours 0.25-24, date not future, within project dates, PRO+ gating) act as preconditions. However, it never names an alternative tool or states when to reach for create vs update_timesheet_entry vs submit_timesheet, leaving routing to inference.

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