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

No annotations are provided, so the description carries the full burden. It discloses that the tool is free, which is a useful behavioral trait. However, it does not describe the return format, potential delays, or whether it performs any side effects (though as an info tool, side effects are unlikely). The description is adequate but not rich in behavioral detail.

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?

Two sentences with zero waste. The primary purpose is front-loaded, and the note about being free is appended clearly. Every word earns its place.

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 zero-parameter informational tool, the description is complete: it tells the agent exactly what information will be provided. It doesn't specify the response format (e.g., plain text vs. JSON), but that's a minor omission given the tool's simplicity and the absence of an output schema.

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?

The tool has zero parameters, and the schema shows no properties. Per the rubric, a 0-param tool gets a baseline of 4. The description adds no parameter-specific meaning because there are no parameters to explain. The baseline score 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?

The description clearly states the tool's purpose: to describe FreshProof, its observation semantics, pricing, and payment network. It uses a specific verb ('describe') and names the exact subjects, making it unambiguous. It also distinguishes itself from the sibling tool 'observe_url' by focusing on informational content rather than observation actions.

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 implies usage (call this when you need info about FreshProof), but it does not explicitly state when to use it vs. the sibling 'observe_url' or mention any exclusions. There is no direct guidance on when not to use it, though the contrast with the sibling is implicit.

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