Lint Rego

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

The description goes well beyond annotations. It discloses the external dependency (`regal` on PATH or `REGAL_BINARY`), the failure mode (`REGAL_NOT_FOUND`), the auto-disabling of path-dependent rules for inline source, and the `<inline>` path substitution. This is excellent behavioral disclosure that cannot be inferred from the schema. The `readOnlyHint: false` is consistent with a lint operation that launches an external process; 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?

The description is compact and information-dense. The first sentence states the core purpose; the second covers dependencies and failure modes; the third explains conditional behavior for inline source. It is front-loaded and every sentence earns its place. A small deduction because the inline-source caveat is long and could be trimmed.

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?

The description covers return categories, dependency requirements, inline-source behavior, and path handling. With 9 parameters and no output schema, the remaining gap is the exact shape of the returned violation objects (e.g., severity codes, rule IDs). Still, for an agent choosing and invoking the tool, the most important operational details are present. Could mention that `paths` must be within allowed roots, but that is already in the schema.

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%, so every parameter already has a description in the schema. The tool description does not repeat parameter details, which is appropriate. However, it also doesn't add semantic context about how `enable`/`disable`/`enableCategory`/`disableCategory` interact or how `failLevel` maps to exit codes beyond what the schema already says. Baseline 3 is fair because the schema carries the load.

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?

States a specific verb ('Lint'), a specific resource ('Rego source'), and names the actual linter ('Regal'). It also specifies returns 'categorized violations (style, bugs, idiomatic, performance) with file/line locations', which distinguishes it from other rego_* tools that analyze, transform, or evaluate Rego.

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 clearly explains how to invoke it with `paths` or inline `source`, and notes the behavior difference for the inline case. It doesn't explicitly spell out 'use X instead when...' alternatives, but the sibling list is large and the description's focus on inline-source behavioral detail implies the relevant context. Slight gap: no explicit statement about when to prefer rego_check, rego_fix, or rego_security_audit over this linter.

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