billing_charges

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

Without annotations, the description does not disclose behavioral traits beyond the date range. No mention of read-only nature, permissions, pagination, or error handling, which are critical 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 with two sentences and parameter definitions, no redundant words, and front-loads the purpose.

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 presence of an output schema and only two simple parameters, the description is adequate. However, it lacks behavioral transparency and usage guidance, making it less complete for an AI agent.

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%, but the description specifies the YYYY-MM-DD format for both start_date and end_date, adding meaning absent from the schema. However, it does not explain the date range semantics (e.g., inclusive/exclusive).

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 the tool lists charges for a subscription with a specific verb and resource. It distinguishes from sibling billing tools like billing_budgets or billing_estimate_cost, which have different purposes.

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 vs alternatives. It does not mention scenarios, prerequisites, or exclusions, leaving the AI agent to infer usage.

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