time.entries.aggregate

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

Annotations already establish readOnlyHint=true, destructiveHint=false, and idempotentHint=true, covering safety and idempotency. The description adds valuable business context about billable hours and date range filtering, but doesn't clarify whether archived entries are included or describe the return structure/pagination.

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?

Two perfectly constructed sentences with zero waste: first establishes the calculation scope and resource, second provides specific business contexts for invocation. Information is front-loaded and efficiently structured.

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?

Given the 100% schema coverage and strong annotations, the description adequately covers inputs and use cases. It mentions calculating 'minutes and hours' which partially compensates for the missing output schema. Minor deduction for not specifying the exact return structure (object vs. scalar) or whether the aggregation includes archived entries.

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 100%, with all four parameters fully documented (project_id, date range fields, billable_only). The description references 'optional date range' and 'billable hours' adding semantic context, but doesn't add technical details (format syntax, constraint logic) beyond what the schema provides. 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?

The description uses specific verbs ('Calculate') and clearly identifies the resource ('total minutes and hours logged against a project') and scope ('over an optional date range'). It effectively distinguishes this from CRUD sibling tools (time.entries.create, list, etc.) by focusing on aggregation/summation rather than entry management.

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 explicit positive guidance with three specific scenarios ('preparing an invoice', 'verifying billable hours', 'generating a summary timesheet report'). However, it lacks explicit negative guidance or contrast with siblings like time.entries.list (which returns individual entries vs. aggregates).

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