Check an employee's remaining leave balance using their employee ID. Use it to confirm available leave before submitting or approving time-off requests.
Check leave balance for an employee
| Name | Required | Description | Default |
|---|---|---|---|
| employee_id | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must disclose behavior. It only states the action; it does not mention read-only nature, permissions required, side effects, or whether it returns current or accrued balance. The output schema covers return values, but behavioral traits are absent.
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?
Single front-loaded sentence with no filler. It is arguably too terse given missing guidance, but from a pure conciseness standpoint it avoids waste.
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 simple one-param read tool, the description covers the core purpose, and the output schema handles return values. Still missing parameter semantics and usage context, leaving an agent to infer format and when to call.
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 0% for the single employee_id parameter. The phrase 'for an employee' merely restates the parameter name and adds no format, source, or validation detail (e.g., whether it is a UUID or email). It fails to compensate for 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?
States a specific verb 'check' and resource 'leave balance' scoped to an employee, making the action clear. It does not explicitly differentiate from siblings like submit_leave_request or approve_leave_request, though the verb implies a read-only query.
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?
No indication of when to use this tool versus alternatives, no prerequisites (e.g., employee must exist), and no mention of related tools. Usage is only implied by the verb.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.