get_invoice

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

Beyond annotations which already indicate this is a safe read operation, the description adds that it returns 'full invoice data including line items and status', providing useful behavioral context about the output.

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?

Two sentences, no wasted words. Every sentence is necessary: first states purpose, second states exclusions and alternatives.

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?

Despite no output schema, the description mentions what data is returned (line items and status). Combined with annotations and clear usage guidance, it is fully complete for a simple retrieval tool.

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 100% for the single 'id' parameter, so baseline is 3. The description does not add additional meaning about the parameter format or constraints beyond what the schema provides.

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 verb ('view') and resource ('details of a specific invoice by its ID'), and explicitly distinguishes from siblings by naming alternatives for listing and cost analysis.

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?

Provides explicit when-to-use ('view details of a specific invoice') and when-not-to-use ('do NOT use for listing all invoices or cost analysis') with named alternatives (list_invoices, run_query).

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