explain_rule

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds that the tool provides impact, fix steps, and verification, which is useful context beyond a generic 'explain'. However, it does not disclose output format, error handling, or any other behavioral traits, so the added value is moderate.

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?

A single sentence that front-loads the action and lists the key outputs. There is no fluff, and it is concise without being under-specified—every word contributes to describing the tool's function.

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?

For a simple tool with one parameter and annotations covering safety, the description is minimal but conveys the purpose. However, it lacks usage guidance and parameter semantics, and it does not contextually place itself among the many sibling tools. An agent would not know when to call it or how to find the rule_id, leaving notable gaps.

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 schema provides only the parameter name 'rule_id' with type string and no description. The tool description does not explain what a rule_id is, how to obtain it, or its format. With 0% schema description coverage, the description wholly fails to compensate, leaving the agent with no semantic context for the sole required parameter.

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 a specific action ('Explain a K-Guard rule') on a specific resource, and lists the content of the explanation (impact, fix steps, verification). This distinguishes it from siblings like suggest_fix, which focuses on proposing fixes rather than explaining a 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?

There is no guidance on when to use this tool versus alternatives like suggest_fix or scan_workspace. It does not mention why one would prefer an explanation over a fix suggestion, nor any conditions or prerequisites, leaving the agent to infer usage.

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