check_guarantees

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

With no annotations, the description carries full burden. It discloses that the tool returns a violations array with node IDs, file, line, rule name, and that an empty array means all pass. It does not mention side effects, but as a validation tool it's expected to be read-only.

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 concise and well-structured: a main statement followed by bullet-pointed use cases and a clear return description. Every sentence is informative with no redundancy.

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 single optional parameter and lack of output schema, the description is complete. It explains purpose, usage, return format, and includes an example, covering all necessary information for an agent.

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 coverage is 100% and the description adds value beyond the parameter description by showing an example of usage with 'names' and explaining filtering. It provides practical context like pre-commit validation.

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 purpose: 'Validate code against defined guarantees and return violations.' It lists specific use cases that differentiate it from siblings like add_assertion or list_guarantees, such as 'Find violations' and 'Verify specific rule'.

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 provides explicit usage contexts: 'Find violations', 'Verify specific rule', 'Pre-commit validation', 'After code changes', and includes an example with the 'names' parameter. It lacks explicit 'when not to use' or alternatives, but the contexts are clear enough.

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