get_invoice

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds no behavioral context beyond those annotations, but it also does not contradict them.

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?

At two words, the description is technically concise but is under-specified rather than efficiently informative. It reads as a label rather than a helpful definition, offering no detail to justify its place in the tool contract.

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 simple single-parameter schema, the presence of an output schema, and safety annotations, the lack of detail is partially mitigated. However, the description is still too sparse to independently guide an agent, especially with sibling list_invoices available and no clarification of the singular fetch behavior.

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 provides 100% coverage: the only parameter, invoice_id, is described as 'Invoice UUID'. The description adds no additional parameter meaning, but the schema fully documents the parameter, meeting the baseline.

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 'Get Invoice' simply restates the tool name and title, adding no new information. It identifies a verb and resource but is essentially tautological, failing to explain what retrieving an invoice entails or how it differs from list_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?

No usage guidance is provided. The description does not specify when to use this tool versus list_invoices or other get_* siblings, nor does it mention that this tool fetches a single invoice by ID.

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