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

With no annotations provided, the description carries the burden of behavioral disclosure. It explains that this tool reports 'observed availability' and 'settlement counts,' suggesting it reflects current state but not necessarily real-time or cached data. It does not specify the output format or whether it causes side effects, but the nature of a status check is clear. No contradictions with annotations (none exist), so a mid-range score is appropriate.

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 sentence that is informative but somewhat long. It front-loads the main purpose ('What this x402 facilitator can settle right now') and includes a clear usage directive at the end. It could be slightly more concise, but every phrase adds value, so it earns a high score.

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 that the input schema has no parameters and there is no output schema, the description provides a comprehensive overview of what the tool reports. It mentions key aspects like live networks, schemes, merchant status, screening state, and settlement counts. For a status-checking tool, this is nearly complete; only a note on return format (e.g., JSON structure) could be added, but other siblings likely share a pattern.

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 input schema has 0 parameters, so the description does not need to explain parameters. However, it adds value by describing the kind of information returned (e.g., networks, schemes, merchant status), which helps the agent interpret the output even without an output schema. Since there are no parameters, the baseline is 4, and the description provides useful context about the tool's scope.

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's purpose: to report the current settlement capabilities of the x402 facilitator, including live networks, schemes, merchant status, address screening, availability, and settlement counts. It uses specific verbs ('settle', 'advertising') and resource names, distinguishing itself from siblings (e.g., settlement_price is likely for querying prices, not status).

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 instructs to call this tool before advertising a price, because a network that cannot settle is withdrawn here first. This provides a clear when-to-use directive and implies it should be checked prior to other operations like settlement_price, effectively routing the agent to this tool at the right time.

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