Get Invoice

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description's 'Get' aligns. However, the description adds no additional behavioral details (e.g., rate limits, authentication requirements, error handling). With annotations, the burden is lower, but the description merely restates the obvious.

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, front-loaded sentence that communicates the essential action without any fluff. It earns its place but could arguably be slightly more detailed (e.g., mentioning the return type) while remaining concise.

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 low complexity (1 param, no output schema, annotations present), the description is functional but minimal. It does not describe the response structure or any edge cases. While the annotations cover safety, the description could be more complete by specifying what is returned.

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 100% coverage with a description for the 'id' parameter. The description does not add any extra meaning (e.g., format, length, examples). According to the guidelines, high schema coverage means a baseline of 3 is appropriate.

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 'Get a specific invoice by ID', which includes a specific verb and resource. It distinguishes itself from sibling tools like 'siigo_get_invoices' (which likely lists multiple) and 'siigo_get_invoice_pdf', making its purpose unambiguous.

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 implies usage for fetching a single invoice by ID, but it provides no explicit guidance on when to prefer this over alternatives (e.g., siigo_get_invoices for multiple invoices) or any prerequisites. The context is implied by the name and sibling set, but not spelled out.

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