Explain an architecture rule

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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the trailing 'Read-only' adds no new information. What does add value is the disclosure of the return contents — statement, gate status, conformance stats, violating files — which compensates for the absent output schema.

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?

A single front-loaded sentence with no filler; the essential action and input come first and the returned fields follow. Slightly dense with its parenthetical examples but each clause carries information.

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?

With no output schema, the description carries the burden of describing returns and does so concretely. It omits edge cases such as an unknown label, the size/pagination of the violating-file list, or whether the path must match the original scan, which keeps it just below full completeness.

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 both parameters are already documented. The description adds a third label example ('lib !-> app') and implies the path default, but contributes little beyond what the schema already states — the baseline 3 when the schema does the heavy lifting.

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 (explain) and resource (one rule from archprint_scan identified by label), and enumerates the exact payload: statement, gate status, conformance stats, and every violating file. An agent can distinguish this from archprint_scan and archprint_recommend without opening any schema.

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 phrase 'one rule from archprint_scan' makes clear this is a drill-down follow-up to a scan and specifies the required identifier (the label). However, it never names an alternative or states when NOT to use it, so it falls short of explicit when/when-not guidance.

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