invoice_cancel

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

With no annotations, the description bears full burden for behavioral disclosure. It states cancellation but omits side effects (e.g., reversibility, impact on related data, permissions needed). This is insufficient for a mutation tool.

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 very short and front-loaded, but it includes redundant formatting (e.g., 'Parameters' section that repeats the schema). It could be more concise or reorganized to front-load key behavior. Still, no wasted sentences.

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 having an output schema and simple parameters, the description lacks essential context for a mutation tool—such as prerequisites (e.g., invoice must exist), idempotency, or success/failure signals. The agent would need to infer too much.

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%, yet the description merely restates the parameter name ('Invoice ID to cancel') without adding type constraints, formatting, or context beyond the schema. It fails to compensate for the low coverage.

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 tool's action ('Cancel (void) an invoice') with a specific verb and resource, and it is distinct from sibling tools like invoice_create or invoice_generate. However, it lacks nuance about what voiding entails.

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 guidance is provided on when to use this tool versus alternatives (e.g., invoice_create or invoice_update_status). There are no exclusions or prerequisites noted, leaving the agent to infer context.

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