x402ai ask

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

Adds substantial context beyond annotations: exact price ($0.04 USDC on Base), expected latency (5-16 s), and the existence of per-payment and per-session caps. This meaningfully complements idempotentHint=false by making clear each call spends real money, though it doesn't say whether a failed or slow call is still charged.

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?

Four short sentences, front-loaded with purpose followed by cost and latency — the highest-value constraints for a paid tool. 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?

For a one-parameter paid tool with no output schema, it covers purpose, price, latency, and spend limits. The gap is the payment mechanics (how authorization happens, whether a wallet must be pre-configured) and what a failed call costs.

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 100% and already documents the single `input` parameter with its 1-3000 character bound. The description's 'Pass the question in `input` (max 3000 chars)' largely restates the schema, so baseline 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+resource: 'Ask a question and get an answer,' which is clearly distinct from embed/summarize style siblings. It does not explicitly name those siblings, so the differentiation is implied 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?

Gives strong decision-relevant context (cost, latency, spend caps) but never states when to choose this over `embed` or `summarize`, nor when not to call it. The agent must infer the boundary from the sibling names.

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