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

Annotations already declare readOnly, idempotent, and non-destructive behavior, so the bar for additional transparency is lower. The description adds valuable context beyond annotations: it is offline ('no network') and enumerates the specific return fields, helping the agent anticipate output despite no output schema. It does not contradict 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?

Two concise sentences: the first states exact output and data source, the second gives usage context. Every word is purposeful, no redundancy or fluff.

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 zero-parameter, read-only list tool, the description plus annotations fully cover purpose, usage, and expected behavior. The explicit mention of t54_x402_request provides clear integration context, making the tool's role in the larger workflow obvious.

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 schema coverage is trivially 100%. With no parameters, the description has no parameter semantics to add, and the baseline for zero-param tools is 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 precisely states the tool returns operationIds, HTTP methods, paths, and query parameter names from the bundled OpenAPI spec. It distinguishes itself from sibling tools by explicitly framing this as a pre-request discovery tool and notes the offline nature ('no network'), which sets clear expectations.

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?

Provides explicit usage guidance: 'Use before t54_x402_request or per-SKU tools.' This tells the agent exactly when to invoke this tool relative to alternatives, giving clear sequencing and context for its role in the workflow.

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