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

Annotations declare it is not read-only, idempotent, non-destructive and open-world, but they say nothing about cost. The description adds critical non-structured context: this costs $9.00 USDC on Base via x402 and that the audit itself attempts no payment. That pricing disclosure is exactly the kind of behavioral detail annotations cannot carry.

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 tight sentences with the cost (the highest-value fact) front-loaded, followed by the scope of checks and the non-payment clarification. No filler; only the first sentence's formatting ('PAID $9.00...') is slightly clipped.

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?

With an output schema present, return values need not be described, and annotations cover the safety profile. The description supplies the missing pieces an agent most needs: price, mechanism (x402) and the reassurance that no payment is attempted. Adequate and well-targeted for a one-parameter audit tool.

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 is a single parameter with 100% schema description coverage ('Public HTTP(S) MCP service base URL to audit'), so the schema already fully documents it. The description adds no syntax or constraint detail beyond that, so the baseline of 3 applies.

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?

Clear verb (audits) plus resource (a public MCP endpoint) with an enumeration of the check types (discovery, health, transport, schema, receiver-only), which meaningfully separates it from a schema-only sibling like mcp.schema_audit. It never names those siblings explicitly, so the differentiation is inferred rather than stated.

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 phrase 'launch audit' and 'public endpoint' implies pre-launch use, but there is no explicit when-to-use/when-not-to-use guidance and no routing to alternatives such as mcp.schema_audit or x402.compatibility_audit. Usage context is implied rather than stated.

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