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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds material behavior beyond that: it is gated to the Pro plan and fails on other plans, requires a Cotlet API key with app access, and defaults to pending results sorted newest first. These are concrete operational constraints not present in the 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?

Front-loaded with the core purpose, but it repeats itself: 'Pro plan' appears twice and the returned fields are listed twice ('policy, dates, hours' then 'the policy, the dates and the hours requested'). These redundant sentences dilute an otherwise compact description.

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 tool with no output schema, the description covers what it returns, the default filter, sort order, and the plan/auth preconditions an agent must satisfy to avoid a failed call. It is essentially complete, with only minor redundancy to clean up.

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% and the single enum parameter already documents pending/approved/declined/all with the same default. The description's 'pending ones by default' merely restates the schema, so it adds no syntax or filtering nuance beyond it. Baseline 3 is appropriate.

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: lists time off requests, and spells out the fields each record carries (employee, policy, dates, hours, status). An agent can distinguish it from the sibling clockshark_respond_time_off_request, though the description never names that sibling explicitly.

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?

Provides useful context: defaults to pending-only, newest first, and is a Pro-plan feature that fails otherwise. However, it gives no explicit when-to-use vs. when-not guidance relative to alternatives (e.g., responding to or approving requests), leaving selection largely implied by the 'list' name.

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