billing_usage_details

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

No annotations are provided, so the description must disclose behavioral traits. It only mentions fetching usage data with date parameters, but omits information about read-only nature, permission requirements, pagination, or any side effects. This is insufficient for a billing tool.

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?

The description is extremely concise, front-loading the core purpose in the first sentence, then listing parameters with clear labels. No wasted words or irrelevant details.

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?

The description covers the basic functionality but lacks usage context, differentiation from siblings, and any mention of output schema or potential limitations. Given the existence of an output schema and sibling tools, a bit more context would improve completeness.

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?

The schema has no descriptions (0% coverage), so the description adds value by providing format (YYYY-MM-DD) for dates and clarifying that resource_group is optional for filtering. However, it doesn't specify the expected format of resource_group (name vs. ID), preventing a perfect score.

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 clearly states 'Get Azure usage details for a subscription', which is a specific verb-resource combination. It distinguishes from sibling billing tools (budgets, charges, estimate cost, periods, reservations) by focusing on usage details.

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 description provides no guidance on when to use this tool versus alternatives like billing_charges or billing_periods. It simply states what it does without context or exclusions.

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