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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds 'Free' but no additional behavioral context like rate limits or data freshness. With annotations covering safety, the description provides adequate but not rich transparency.

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 one concise sentence with a list of contents followed by 'Free.' It is front-loaded with the main purpose, no wasted words, and is easy to parse quickly.

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, no-output-schema tool with good annotations, the description covers the main metrics. It could mention data update frequency, but given simplicity, it is reasonably complete.

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?

There are zero parameters, and schema coverage is 100% (trivially). Per guidelines, baseline is 4 for zero-parameter tools. No additional parameter description is needed.

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 it provides 'Live health of the whole x402 agent-payment ecosystem' and enumerates specific metrics (tracked/alive/dead counts, catalog-accuracy audit, risk-level distribution, etc.), which clearly distinguishes it from sibling tools like check_x402_endpoint or x402_incidents.

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 says 'Free' but offers no explicit guidance on when to use this tool versus alternatives like check_x402_endpoint or x402_leaderboard. The list of contents implies it's for an overview, but lacks when-not or alternative suggestions.

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