explain_rules

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

No annotations are supplied, so the description carries the full behavioral burden. It implies a read-only lookup by saying 'Return,' and adds genuine context that the response includes authority/provenance, but it never states whether the rules are global or project-specific, whether the result is static or recomputed, or how large the payload is. With zero annotation coverage these are meaningful omissions.

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?

It is a single front-loaded sentence with the action first and the motivating examples second; nothing is redundant. The trailing clause 'so the answer ... is traceable' is slightly indirect relative to the rest, but it earns its place by explaining the value of the call.

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 tool is simple: zero parameters and an existing output schema, so the description need not describe return values. It successfully conveys purpose and the motivating scenario, leaving only the global-vs-project scope question unresolved, which is a minor gap given the surrounding inspect_project sibling.

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 tool takes no parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description does not introduce any spurious parameter-like concepts such as a rule id or project scope, which keeps expectations aligned with the empty schema.

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 names a specific verb and resource: 'Return the layout rules and their authority.' That is clearly distinct from siblings like inspect_project, estimate_material, or generate_materials, since this tool surfaces the rationale behind rules rather than project state. It stops short of stating exactly what a 'layout rule' contains, so it is clear but not fully discriminating.

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 two quoted questions ('why 50 lines', 'why is the page number top right') imply when to reach for it: when a user or agent needs the justification behind an existing layout decision. However, it names no alternatives and gives no exclusions, so an agent must infer that review_manual or inspect_project are not the right picks for a 'why' question.

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