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

With no annotations, the description carries the behavioral burden and does disclose the most decision-critical traits: it is a paid call ($0.02 USDC, x402, eip155:8453) and it returns an ordered list of concrete fixes. The cost/payment gate is real context an agent must know before invoking. Gaps remain around data freshness, how many origins are ranked, and whether results are cached, but the core behavior is covered.

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?

Three sentences, front-loaded with the payment qualifier and then the payload and audience. Every sentence adds information (cost, contents, use case). The payment metadata is packed into a bracketed prefix, which is dense but does not obscure the following content.

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?

There is no output schema, so the description must describe returns, and it does so by listing the exact fields returned. For a zero-parameter list tool this is close to sufficient; what is missing is the size and freshness of the ranking set, which an agent would want when deciding between this and a per-site scan.

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, so there is no parameter semantics to explain beyond confirming the call is argument-free, which the empty schema already establishes. Baseline 4 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?

The description gives a concrete verb-and-resource picture: it returns the worst discoverability failures measured across real x402 origins, and it enumerates the payload (score, verdict, missing documents, blocked AI bots, OpenAPI defects, ordered fixes). That is far more specific than the bare name 'repair_priority'. It does not, however, name or distinguish itself from the obvious sibling repair_scan, which is the one ambiguity left.

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?

Usage context is explicit: 'For an operator or directory that wants to know who to help, partner with, or learn from', which tells the agent this is a cross-origin ranking for a portfolio-level audience rather than a single-site repair. 'Cheaper than scanning yourself' implies the alternative. No explicit exclusions or named sibling alternatives, so it stops short of a 5.

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