get_invoice

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

With no annotations provided, the description must fully disclose behavior. It mentions a behavioral trait (requires Accounting permission) but does not describe return format, error handling, or side effects. For a simple read operation, this is basic but could be richer.

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 a single sentence with no extraneous words. It efficiently communicates the tool's core purpose and a key requirement.

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 simplicity (one parameter, no output schema, no annotations), the description is fairly complete in stating purpose and a permission need. However, it lacks explanation of the return value and error conditions, which would be expected without an output schema.

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 input schema has one parameter with no description. The description adds no meaning beyond 'by ID', failing to explain what the invoice ID represents or its format. Schema coverage is 0%, so the description should compensate but does not.

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 specifies the verb 'Get', the resource 'one invoice', and the identification method 'by ID'. It distinguishes from sibling tools like list_invoices that retrieve multiple invoices.

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?

It states a permission requirement ('needs Accounting permission'), which informs when the tool can be used. However, it does not explicitly contrast with alternatives or provide exclusion criteria. The context implies this is for a single invoice vs. list_invoices for multiple.

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