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

With no annotations, the description carries the full burden, and it does disclose one key behavioral trait: this channel refuses paid work and defers payment collection to the x402 HTTP surface. It omits what the caller actually receives on invocation (error payload, empty result, redirect) and whether any auth is needed to reach the HTTP path.

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?

A single terse sentence that front-loads the refusal and names the escape hatch. It is efficient, though the dash-and-parenthetical phrasing is slightly cryptic and leans on jargon ("x402 surface") that a reader may not parse 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 zero-param, no-output-schema stub the description covers the essential redirect, but it leaves unresolved what the tool does at all when called and what the caller should expect back. For a tool whose entire behavior is a refusal, that missing detail is the most important thing an agent needs.

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 takes zero parameters and the schema is trivially complete, so there is nothing for the description to add. Baseline 4 applies for a no-argument tool.

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 communicates the operation's outcome — it refuses paid work over MCP — but never says what a "channel_verdict" actually is or what the tool returns when called. It is differentiated from siblings only implicitly by naming the HTTP surface, not by contrast with cbdr_info, grounded_verification, or verify_receipt.

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 names the alternative surface (POST /verdict over HTTP x402) for paid work, which is genuine routing guidance. However it never states when this MCP tool itself is the right call — whether free/unpaid verification passes through, or whether any invocation always yields a refusal.

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