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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds meaningful context: the tool is free, uses fixed examples, runs through the same checker, and is meant to preview report shape.

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 that starts with the key qualifier 'Free.' It is efficient, though the long parenthetical listing all six examples makes it somewhat dense.

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 simple one-parameter demo tool with full enum coverage and clear annotations, the description supplies everything needed to call it correctly. It explains cost, purpose, relationship to presign_check, and that the output is a sample report shape.

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?

Schema coverage is 100% and the enum values are documented, so the schema carries most parameter meaning. The description still adds readable semantics for each example, such as 'never-expiring permit' and 'normal x402 payment,' which clarifies what the enum selects.

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 gives a specific verb and resource: it runs a fixed example through the same checker used by presign_check. It also differentiates the tool from its sibling by emphasizing that this is a free demo intended to show the report shape before paying.

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?

It explicitly states the usage condition: use this to see the report shape before paying for presign_check. The alternative is named directly, so the agent can distinguish demo usage from real paid checks.

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