list_billing_evn

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

No annotations are provided, so the description carries full responsibility. It states the tool outputs per-resource usage intervals grouped by datacenter, but does not disclose behavioral traits such as read-only nature, authentication needs, or rate limits. The description is minimally transparent.

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 concise with two sentences. The first sentence clearly states the main purpose, and the second briefly mentions an alternative output format. It is front-loaded but could be slightly more 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 tool has one required parameter and no output schema, the description explains the basic functionality and grouping. However, it lacks details on the return structure or example usage, which would help an agent fully understand the output with no schema present.

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% with the parameter 'contract' already described as 'contract number from get_billing_profile'. The description adds no further semantic value beyond the schema, just reiterates 'for your contract'. Baseline score of 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?

Description clearly states the tool retrieves provisioning itemized data (EVN) for the current billing month, showing per-resource usage intervals grouped by datacenter. It differentiates from sibling tools like list_billing_evn_by_period by specifying the scope as 'current billing month'.

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 indicates usage for the current billing month and mentions an alternative for FOCUS v1.3 compliant output. It implicitly contrasts with list_billing_evn_by_period, but does not explicitly state when not to use it.

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