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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), yet the description adds material context beyond them: the member/manager permission model, the PRO+ timeTracking plan gating requirement, and truncation/total semantics. These are behaviors an agent cannot infer from structured fields.

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 and front-loaded: purpose first, then visibility rules, filter modes, status values, and return semantics in logical order. Every sentence carries load; 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?

With no output schema, the description compensates by explaining total and truncated, and it flags the plan prerequisite. Combined with full schema coverage, an agent has everything needed to invoke and interpret the result.

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 baseline is 3, but the description adds value beyond it: it names the concrete status values (DRAFT/SUBMITTED/APPROVED/REJECTED) absent from the schema's enum-less oneOf, explains weekStart as a Monday-based 7-day window, and clarifies the OR relationship between the two date modes.

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 (List) and resource (timesheet entries) and immediately clarifies scope of data returned. An agent can distinguish this from sibling tools like list_timesheet_approvers or create_timesheet_entry without opening the 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?

Explicitly describes when the tool returns own vs org-wide entries based on role and whether userId is passed, and lays out the two mutually exclusive filtering modes (weekStart vs startDate+endDate). This is genuine when-to-use and alternative-selection guidance.

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