Describe validation rules

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description's 'Read-only, no side effects' is redundant but harmless. The description adds meaningful behavioral context beyond annotations: it explains the merge order of defaults, config file, and inline overrides, and describes the return structure (commit_check_version, merged config, supported_checks, enabled_rules). This is useful context that annotations do not provide.

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 sentences long, with the purpose front-loaded in the first sentence, the return structure in the second, and usage guidance in the third. It is concise and every sentence adds value. It could be slightly tighter by merging the first two, but it is well-structured and not verbose.

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 moderate complexity (3 optional parameters, an output schema, and several siblings), the description is complete. It explains what the tool returns, when to use it, and the merging semantics. The output schema covers return details, so the description doesn't need to repeat them exhaustively. It covers the key contextual points an agent needs to invoke it 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 each parameter is already well-documented in the input schema. The description does not add syntax or format details for the parameters, but it does reference config_path and 'inline config overrides' in the context of merging, which reinforces their role. This meets the baseline of 3 for high schema coverage; no additional compensation is needed.

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 states a specific verb ('Return') and a precise resource ('commit-check rules that are in effect after merging...'). It clearly distinguishes this describe tool from the sibling validate_* tools, which perform validation actions rather than describing rules. The merging behavior is explicitly articulated, leaving no ambiguity about what is returned.

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 final sentence gives explicit when-to-use guidance: 'Use this before writing a commit message or branch name to learn the expected format instead of guessing, and to debug why a validation failed or was skipped.' This tells the agent exactly the scenario for this tool versus the validation siblings, and even mentions the alternative of guessing. It effectively routes the agent to the right tool.

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