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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds that the tool is 'FREE' and that it describes 'safety boundaries,' which gives some context about cost and content. However, it does not disclose what the actual output looks like (text, structured data, etc.) or whether any side effects occur, though annotations suggest none. It adds modest value beyond the annotations.

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 concise sentence, front-loaded with 'FREE.' It is efficient with no wasted words. The key purpose and boundaries are stated directly.

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 tool with annotations covering safety, the description is mostly adequate. However, it lacks specifics about what the agent will receive in the response (e.g., a plain-text overview, a structured object, a list of boundaries). The description is complete enough to make the call, but the output format is left to inference, which could lead to ambiguity.

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 has zero parameters, so the description does not need to explain parameter semantics. The schema covers the empty parameter set. Baseline 4 is appropriate.

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 specific verb ('Describes') and a clear resource ('the receiver-only CrossingKey machine-commerce service and its safety boundaries'). It distinguishes itself from siblings by being a meta-level overview rather than a specific capability operation, though it doesn't explicitly contrast with any sibling. The purpose is clear and not a tautology.

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?

No guidance is provided on when to call this tool versus its siblings. The description does not mention typical use cases, prerequisites, or alternatives. An agent would have to infer that this is an introductory or overview tool, but that is not stated.

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