billy_list_invoices

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

With no annotations, the description must fully disclose behavior. It notes READ-ONLY and lists filters, but fails to mention pagination behavior (page, pageSize), output format, or any rate limits or authentication details. This is insufficient for a tool with 6 parameters and no output schema.

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 short sentences that front-load the core purpose and key parameters. Every word adds value, and there is no redundancy.

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 6 parameters, no output schema, and moderate complexity (filtering and pagination), the description is incomplete. It omits pagination details, output format, and parameter constraints. An AI agent would need additional context to use the tool correctly.

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 0%, and the description only partially compensates by listing 4 of 6 parameters as filters. It does not explain the format of sinceDate/untilDate, the purpose of page/pageSize, or add semantics beyond the schema's basic types. The enum for state is already present in the schema.

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 explicitly states the verb 'List' and resource 'invoices', clearly differentiating from sibling tools like billy_create_invoice or billy_approve_invoice. The READ-ONLY tag further clarifies the tool's safe nature.

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 the tool is READ-ONLY and lists available filters, providing basic guidance. However, it does not explicitly state when to use this tool versus other list tools or exclude inappropriate scenarios, leaving room for interpretation.

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