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

Annotations already declare readOnlyHint, idempotentHint, and closed-world, but the description adds genuinely new behavior: no target fetch, no demand, and no payment occur. That is meaningful side-effect disclosure beyond the structured fields, though it does not cover return shape or failure modes.

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 short, front-loaded sentences with no filler; the key guarantee (free, no side effects) is stated immediately.

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 9-parameter tool with nested objects, no output schema, and 0% schema coverage, the description is far too thin. An agent cannot know how to fill most parameters or what the preflight returns.

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?

With 9 parameters at 0% schema description coverage, the description must carry the burden, but it only vaguely gestures at "input" and "price" (mapping loosely to inputs and economics). The client, output, urgency, freshness, return_path, and capability_id parameters are entirely unexplained.

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?

States a specific action (preflight of input/price) and its scope (free, before a paid endpoint invocation), which distinguishes it from the paid sibling request_capability. It is clear but leaves the exact output of the preflight unstated, so an agent must infer what it gets back.

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?

"Before a paid endpoint invocation" implies the timing condition, so usage is implied rather than explained. No sibling is named (e.g., request_capability) and there is no explicit when-not guidance, so routing is left partly to inference.

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