get_usage_stats

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

No annotations are present, so the description carries the burden. It discloses that this returns organization-level aggregate statistics, which implies read-only behavior, but it does not explicitly state that no data is modified, who can access it, or any limitations on the aggregation. This is acceptable but not thorough.

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?

First sentence is front-loaded with the core function and key output metrics. The second sentence is somewhat generic but reinforces the use case; overall there is little wasted text.

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 and no annotations, the description must cover return semantics. It lists the main metric categories but does not mention output format, grouping, or how filters interact with the aggregate result. Sufficient for basic invocation but leaves some ambiguity.

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%, so the schema already explains start_date, end_date, and agent_name. The description adds no parameter-level detail, but it also does not need to; 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 states a specific verb and resource ('Get call usage statistics for your organization') and enumerates the output categories (total calls, duration, costs, status breakdown). It is clear, though it does not explicitly contrast itself with sibling tools like get_call_logs beyond the implicit aggregate-vs-logs distinction.

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?

'Useful for understanding usage patterns and costs' gives a soft use case, but there is no explicit guidance on when to choose this over get_call_logs or other siblings, nor any exclusions. The usage context is implied rather than stated.

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