Explain a rule

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

Annotations already mark the tool read-only and closed-world. The description adds value by specifying that it returns the full rule and the statute, and importantly warns to use the `authority` field as the citation rather than substituting a remembered one. This gives behavioral guidance beyond the structured annotations.

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 three short sentences, front-loaded with the main purpose and followed by a use case and a caveat. Every sentence carries necessary information; no fluff or 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?

For a one-parameter, read-only tool with an output schema, the description covers the purpose, the trigger for use, and the critical caveat about the authority field. The runtime context (finding IDs, rule IDs) is referenced in the schema. Nothing essential is missing for correct invocation.

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 single parameter `rule_id` is fully documented in the schema (100% coverage) with a clear description and example. The tool description does not add anything about the parameter, so the schema baseline of 3 applies.

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 opens with a specific action and object: 'Return the full rule behind a finding, including the statute it rests on.' This clearly states the tool's function and scope, and the second sentence adds the use context (before explaining why text was flagged). It does not explicitly name or contrast sibling tools, so it stops short of full differentiation.

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 explicitly instructs when to use the tool: 'Use this before telling anyone why their text was flagged.' This is clear contextual guidance. No exclusions or alternative routing is provided, but the context is enough to avoid misuse among siblings.

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