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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, non-mutating read. The description adds the return structure (CWF PLAN lines and SETTLE line) and the fact it's machine-readable, which is useful. However, it doesn't disclose details like pagination, rate limits, or whether the output is always complete, but given the annotations, the description adds adequate context without contradiction.

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 three sentences long, front-loads the core purpose, and each sentence adds distinct value: what it lists, why it's useful, and what it returns. There is no fluff or redundancy; it is appropriately sized and well-structured.

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?

Given zero parameters, no output schema, and annotations covering safety, the description is complete. It covers what the tool does, why the agent would use it, the output format, and downstream actions (open_payment, escalation). An agent can confidently decide when and how to invoke it without missing information.

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, and the schema is empty. The description explains what the output contains, which is the closest to parameter semantics here. Since there are no parameters to document, the description adds value by detailing the return format, making the tool's behavior fully understandable without needing parameter documentation.

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 clearly states the tool lists plans, costs, and what each plan raises (call ceiling, row budget, commercial indicator set). It distinguishes itself as a machine-readable alternative to parsing a pricing page, and explicitly mentions the output format (CWF PLAN lines and a SETTLE line). This is specific and unambiguous.

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 provides strong usage context: it is for deciding what to do about a refusal without parsing a pricing page, and it routes the agent to alternative actions (buy the plan yourself with open_payment, or escalate to whoever holds your budget). This is explicit when-to-use and names related actions, though it doesn't name a sibling tool for comparison; still, the guidance is clear and actionable.

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