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

With no annotations provided, the description carries the full burden of disclosure, and it does well by stating it is unpaid, fail-closed against SSRF, returns readiness/claimed-vs-observed/flags, and does not charge. It does not detail network side effects or auth requirements, but for a simple probe tool the disclosed behavior is reasonably transparent.

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 description is extremely compact: three short sentences, front-loaded with the core purpose and key differentiator ('Unpaid probe'), then follow-up on behavior, result, and cost. Every sentence earns its place with 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?

Given the low complexity (one required parameter), the existence of an output schema to cover return details, and the description's coverage of cost, safety posture, and result categories, the definition is adequately complete. The main missing piece is explicit guidance on when to choose this tool over preview/route, but that is largely a usage-guideline concern.

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%, with the url parameter already described as an https URL of the seller endpoint to probe. The description adds no additional parameter semantics beyond restating 'seller URL'.

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 clearly identifies the tool as an unpaid probe that determines whether a seller URL is agent-ready, with a fail-closed SSRF posture. It names the specific resource (seller URL) and the type of result (readiness, claimed vs observed, flags). It does not explicitly differentiate itself from siblings preview and route, but the resource and action are distinct enough.

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?

The phrase 'Unpaid probe' and 'Does not charge' imply the tool is appropriate for a no-cost validation check before committing to paid or deeper operations. However, it does not explicitly state when to use validate versus preview or route, nor does it describe any exclusions or alternatives.

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