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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description's 'Return' is consistent with these hints but adds no new behavioral context, such as the nature of the rules or any side effects. With annotations carrying the safety profile, the description provides minimal extra transparency, so a 3.

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 a single, front-loaded sentence with no filler. It communicates the core action and object efficiently. Full marks for conciseness.

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 no-parameter, read-only retrieval tool, the description is reasonably complete. However, without an output schema, the agent is left to infer the structure or format of the returned 'rules,' which are described in domain-specific terms. This is adequate for a simple getter but leaves some ambiguity, so a 3.

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 accepts zero parameters, so there are no parameter semantics to clarify. The description's mention of 'rules' does not add parameter-related meaning, but none is needed. Per the rubric, 0 params warrants a baseline of 4.

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 clear verb 'Return' and identifies the resource as 'shared authority and truth rules for machine commerce.' It does not explicitly contrast with sibling tools, but the resource is distinct enough from services, offers, order status, and checkout to infer its purpose. This is clear but lacks sibling differentiation, so a 4.

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 gives no guidance on when to invoke this tool versus alternatives. There are no conditions, caveats, or references to sibling tools. This is a clear absence of usage direction, so a 2.

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