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

With no annotations, the description carries the full transparency burden, and it succeeds: it discloses the cost, the no-LLM guarantee, the recommendation-only behavior, the absence of invocation or second payment, and the degraded local-only fallback when the environment variable is missing.

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 dense and front-loaded with fee and purpose. Every sentence contributes meaningful operational detail (ranking factors, no LLM, no invocation, fallback behavior). It is longer than minimal, but the additional clauses justify themselves.

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?

The output schema covers return structure, but parameter usage remains ambiguous due to 0% schema description coverage and no param-level elaboration in the description. The behavioral and failure-mode context is strong, so the tool is not under-specified overall, but an agent may struggle to populate 'query' vs 'capability' correctly.

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?

Schema description coverage is 0%, so the description must explain parameters, but it does not name or define 'query', 'capability', 'constraints', or 'preferences'. It references 'hard constraints' and ranking factors like price/latency/reliability, which loosely map to the schema, but the crucial distinction between 'query' and 'capability' is left unstated.

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 a specific action ('Finds and ranks') on a distinct resource ('machine-payable MCP services and x402 HTTP endpoints'). It also clarifies the non-execution boundary ('Returns a recommendation only'), which differentiates it from provider-invoking tools.

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 gives clear context for when to use the tool: 'before your agent chooses or pays a provider'. It also explains that it never invokes the provider or makes a second payment, which implies it is a pre-payment routing step. It does not explicitly name alternative tools or exclusions.

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