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

With no annotations, the description must disclose behaviors. It reveals the free one-per-wallet constraint and 'no payment', but omits critical claim mechanics: it requires a signed message, a repeat claim returns 409, and the output format is unknown. The deterministic nature is mentioned, but the description fails to convey the claim endpoint behavior and side effects.

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 a single concise sentence that front-loads the 'FREE' aspect. However, it is under-specified and lacks a structured explanation of the tool's purpose or usage. It is not verbose, but the brevity comes at the cost of missing essential context.

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?

This is a complex tool requiring a signed claim and involves payment semantics, yet the description provides no overview of the claim process, expected output, or relationship to paid analysis. The signature schema helps, but the overall description is incomplete for an agent to know how to successfully invoke it and handle edge cases like repeat claims.

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%, so every parameter (url, task, payer, signature) is documented. The signature description is particularly detailed, explaining the exact EIP-191 message and the 409 response on repeat. The tool description adds no parameter-level value, but the schema already carries the burden, warranting the baseline score.

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 the tool performs 'one real deterministic visual analysis' but does not specify the exact verb (e.g., analyze) or the resource/task types (classification, accessibility, etc.). It implies analysis but is vague about scope, and does not clearly distinguish itself from the sibling webcap_analyze beyond the free aspect.

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 description hints at a free/paid distinction ('FREE (one per wallet)' vs 'Model-backed analysis stays paid') but never explicitly names the paid alternative or when to use it. It also does not mention how this trial claim differs from trial claims for audit, capture, extract, or map_lite. Usage guidance is implied, not stated.

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