Format Rego files in place

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

Annotations declare destructiveHint=true and idempotentHint=true. Description adds details: writes to disk, dryRun preview, abort on parse failure. No contradiction.

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?

Concise, front-loaded with main action, then key features (dryRun, return value, sibling differentiation, flags, error behavior). Every sentence adds value.

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 mutation tool with 5 params and no output schema, description covers return format, error behavior, version flags, and safety. Could mention idempotency or permissions, but redundant with annotations.

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 coverage is 100%. Description adds meaning: paths must be within allowed root, dryRun for preview, regoV1 adds import rego.v1, v0Compatible/v1Compatible for version-specific formatting.

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?

Clearly states the tool runs `opa fmt --write` to format Rego files in place. Distinguishes from sibling `rego_format` by noting this writes to disk vs returning a string. Lists version flags.

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?

Explicitly recommends using `dryRun: true` for preview and distinguishes from `rego_format`. Mentions abort on parse failure. Could explicitly state when not to use, but differentiation is sufficient.

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