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

With no annotations, the description carries the full behavioral burden. 'Get facts + sources' hints at the return shape, but nothing is said about cost/x402 payment, rate limits, latency, source reliability, or whether the tool can answer anything versus only data questions.

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?

One short sentence, front-loaded with the capability. The 'Data Agent:' prefix merely restates the tool name, but there is otherwise no padding.

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 generic Q&A tool with no output schema and no annotations, the description should carry the load, yet it omits return format, cost, sourcing behavior, and parameter meaning. An agent has no basis to call it correctly versus its many clones.

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?

Three parameters (q, query, topic) at 0% schema description coverage, and the description never explains any of them. The overlapping q/query/topic trio is genuinely ambiguous and the description does nothing to disambiguate which field to populate or how they interact.

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 does state a verb+resource ('AI data lookup: ask any question, get facts + sources'), so the agent knows it is a free-form Q&A tool that returns sourced facts. However, it draws no boundary against the many near-identical siblings such as x402-ai-ask, x402-ai-data, x402-data, x402-fact-check, or x402-web-search-deep, so an agent cannot tell which of these to pick.

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?

There is no when-to-use guidance, no when-not-to-use condition, and no named alternative. In a sibling list crowded with generic AI/answer tools, the absence of routing guidance is a real gap.

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