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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), and the description adds non-annotation context: it is free and rankings refresh as monitoring runs every 30 minutes. That freshness cadence is genuinely useful for an agent deciding whether to re-query, though nothing is said about pagination or result-size behavior.

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 core purpose before the sibling routing, and every clause carries information. Slightly dense when enumerating returned fields, but no filler.

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?

An output schema exists, so return values need not be enumerated in prose, and the description still names the key fields and the ranking rule. Combined with annotations and a fully documented parameter, an agent has what it needs to call this correctly; only pagination/truncation behavior is left unstated.

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 coverage is 100% and the single limit parameter is fully documented with range and default in the schema. The description adds no syntax or meaning 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?

States a specific verb (List) and resource (x402 endpoints) with explicit inclusion criteria (verdict proceed or caution, no payout-wallet incidents), ordering (best first), and returned fields (score, grade, verdict, test-payment delivery). An agent can distinguish this from check_endpoint and get_full_report without opening a schema.

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?

Gives both the positive use case ('discover reliable endpoints or pick between providers') and explicit routing to alternatives ('To evaluate one specific endpoint use check_endpoint; to approve a payment use check_payment'). The when-to-use decision is fully specified.

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