list_billing_history

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

No annotations are provided, so the description must fully disclose behavioral traits. It mentions the tool lists billing history with transaction details, implying a read-only operation, but does not address critical aspects like pagination behavior (beyond the 'per_page' parameter), rate limits, authentication requirements, or error handling. This leaves significant gaps in understanding the tool's behavior.

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 well-structured and concise, with a clear purpose statement followed by parameter and return value sections in three sentences. There is no redundant information, and it efficiently conveys the essential details without unnecessary elaboration.

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's moderate complexity (2 parameters, no output schema, no annotations), the description is minimally complete. It covers the basic purpose and parameters but lacks details on usage context, behavioral traits, and output structure. This makes it functional but insufficient for fully informed tool selection and invocation.

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 description adds minimal semantics beyond the input schema, which has 0% description coverage. It explains that 'days' is the 'Number of days to include' and 'per_page' is the 'Number of items per page', but does not clarify constraints (e.g., valid ranges) or interactions between parameters. With low schema coverage, this partial compensation is adequate for a baseline 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 the tool's purpose: 'List billing history for the specified number of days.' It uses a specific verb ('List') and resource ('billing history'), and the scope ('for the specified number of days') is well-defined. However, it does not explicitly differentiate from sibling tools (e.g., 'list_invoices' or 'get_invoice'), which prevents a score of 5.

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. It mentions the default parameters but does not specify scenarios or prerequisites for usage, nor does it reference any sibling tools for comparison. This lack of contextual guidance limits its effectiveness for an AI agent.

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