create_invoice

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

No annotations are provided, so the description carries the full burden. It discloses that the tool creates an invoice (a mutation), but does not mention any side effects, authorization needs, rate limits, or success/failure response details. The description is minimal and does not add much beyond the basic action.

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 three sentences that cover purpose, parameter type, and error handling. It is front-loaded with the HTTP method and endpoint. No redundant information, though it could be slightly more structured with a clear parameter format description.

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 parameter (fields_json) that should contain the invoice body, the description lacks critical details about the expected JSON structure. The presence of many sibling tools and an output schema (not shown) suggests more context is needed. Relying on API validation errors is insufficient for correct tool 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 schema has 0% description coverage for the single parameter (fields_json). The description adds value by stating it is a JSON object for the invoice body, which is not present in the schema. However, it does not specify the expected structure or required fields within the JSON, leaving the agent to rely on trial and error via API validation errors.

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 creates an invoice via a specific HTTP endpoint (POST /v1/invoices). The verb 'Create' and resource 'invoice' are unambiguous. However, it does not explicitly differentiate from sibling tools like 'generate_invoice', which may have a similar purpose.

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 lacks guidance on when to use this tool versus alternatives (e.g., generate_invoice). It does not mention prerequisites, required permissions, or context for use. The only indirect usage hint is that API validation errors will name missing fields, which is more about error handling than usage context.

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