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

With no annotations, the description carries the full behavioral burden and does so well for the cost model: probing is free, requires no signing or spend, a match returns payment details (0.01 USDC x402), and a non-match is free. It does not disclose rate limits, caching, or what a 'shelf' semantically contains, but the payment/auth behavior is unusually well surfaced.

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 tightly packed sentences with no filler, front-loading the core action and the free/no-signing guarantee before the payment details and follow-up path. The dense jargon is efficient, though slightly cryptic on first read.

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 2-param tool with no annotations and no output schema, the description adequately explains the return contract (URL plus payment details) and the cost/free condition. The gap is the entirely undescribed 'params' object and the opaque 'shelf' concept, which an agent needs in order to call it 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% across 2 parameters, so the description must compensate and largely fails to. 'Selected shelf' weakly implies shelf_id is a shelf identifier, but the 'params' object — the only channel for actual query input, and a nested object — is never explained, leaving its keys and accepted value types undocumented.

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 verb ('Probe') and resource ('a selected shelf') and clarifies the output is a GET URL plus x402 payment details rather than the answer itself. This distinguishes it from a straightforward read, though it never names or contrasts with siblings like search_intelligence or list_intelligence, so an agent must infer the boundary.

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?

Usage is implied through the probe-then-buy workflow: this is the free preview step, and the actual purchase happens via the returned HTTP URL with an independent x402 client. However, there is no explicit statement of when to choose query_intelligence over the sibling intelligence tools.

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