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

Annotations already mark this as read-only and idempotent, and the description adds valuable behavior: paginated structured records, no-match returns an empty array, invalid input returns an argument error, and no legal inference is made. This goes well beyond the structured fields.

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 front-loaded with the main purpose and stays compact while covering outputs, limitations, and edge cases. There is minor redundancy between 'Inputs: rule_number' and 'Required: rule_number', but overall the structure is efficient.

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 read-only, parameter-light lookup tool with no output schema, the description is complete: it names the return fields, states pagination behavior, explains empty results, and documents error behavior. An agent has enough to call and interpret the result correctly.

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%, so the parameters are already well documented. The description mentions rule_number and pagination/limits but adds little semantic detail beyond what the schema provides, so the baseline score of 3 is appropriate.

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 verb and resource: 'Find recorded versions and dates for a CCC rule number.' This clearly differentiates it from sibling tools by focusing on rule version history rather than products, standards, or trade statistics.

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 gives practical usage context by noting it returns 'recorded version facts only' and clarifying it 'does not infer legal applicability.' This is a useful boundary, though it does not explicitly name alternative tools for other use cases.

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