explain_validation

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

No annotations are provided, so the description must convey all behavioral traits. It states the tool explains a failure by referencing a rule, but it does not disclose whether it modifies state (likely read-only), whether it requires specific permissions, or what happens if the ruleId is invalid. The description is basic but not misleading; it covers the core behavior without hidden concerns.

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 a single sentence with no unnecessary words. It is front-loaded with the verb and resource, making it easy to parse. Every word contributes to understanding the tool's purpose.

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 simplicity (one parameter, no output schema, no nested objects), the description is sufficient. It explains what the tool does and the source of its input. While it could mention the return value, it is not critical for a tool that 'explains' a failure. Annotations are absent, but the description covers the essentials.

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 input schema has 100% coverage, so baseline is 3. The description of the parameter ('Validation rule ID from validate_code') adds meaning beyond the schema by specifying the source of the ID, which aids the agent in understanding where to obtain it. This extra context justifies a score of 4.

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 verb 'explain', the resource 'validation failure', and the mechanism 'referencing the repository rule'. It distinguishes from sibling tools like 'validate_code' (which produces failures) and 'read_rule' (which reads rules). The purpose is specific and unambiguous.

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 implies usage after validation failures from 'validate_code' (the parameter description mentions 'ruleId from validate_code'), but it does not explicitly state when to use this tool versus alternatives, nor does it provide any exclusions or prerequisites. The usage context is only implied, not directly spelled out.

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