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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds substantive context beyond them: the $0.01 call cost, the REST endpoint, the evidence source per target type (on-chain ERC-8004 vs Bazaar demand), and a genuine limitation ('wallet_flow is marked not_available' for seller targets). Disclosing a known data blind spot is exactly the kind of behavior an agent needs before trusting the verdict.

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 critical routing information (what it is, when to call it, what it returns, how to target) is front-loaded and dense. It runs somewhat long, and the closing 'Not investment advice' is boilerplate that doesn't earn its place, but nothing substantive is padded.

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, the description needn't detail the return shape, yet it still summarizes the verdict fields (action, confidence, expected loss) at the right level. Combined with per-target evidence explanations and the sibling pointer, an agent has everything needed to call this 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 carry all five parameters — and it does, with meaning and mutual exclusivity for each: agent_id, solana_asset (alternative), seller_url (alternative target), pay_to (with 'EVM 0x… or Solana base58' format guidance), and amount_usd (the USDC amount about to be paid). This fully compensates for the bare schema.

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 states a specific decision verb and resource — a pre-payment risk assessment that returns PAY / CAUTION / SKIP with confidence and expected loss — and immediately names the sibling/alternative (agent_interact_gate) it is not. An agent can distinguish it from check_base_token_safety because the scope is agent/seller reputation rather than token contract safety.

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 gives an explicit trigger ('call it before every payment to an unknown agent or x402 seller') and an explicit exclusion with a named alternative ('use agent_interact_gate instead when the question is broader than payment'). The cost-of-use tradeoff ($0.01 to avoid losing $N) further justifies when the call is worth making.

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