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

Goes well beyond annotations by disclosing the rate limit (a few scans per hour per client), site-owner opt-out handling, the read-only-on-target-page scope, and the crucial caveat that this is an automated surface check and not an audit or legal advice. Annotations declare openWorldHint and idempotentHint but say nothing about limits or opt-outs, so the description adds substantial value.

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?

Purpose and return payload are front-loaded in the first sentence, followed by behaviour, caveats, and operational constraints in tight sentences with no filler. It is dense but every clause contributes information an agent needs.

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?

With no output schema, the description correctly enumerates the returned signal categories so the agent knows what comes back. It also covers limits, opt-outs, response-shape caveats, and batching constraints, leaving no material gap for a single-parameter tool.

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% and there is a single parameter, so the schema already carries the load; baseline 3 applies. The description slightly enriches it by stressing the address must be public and singular, but adds no format or edge-case guidance beyond the schema's example.

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?

States a specific verb and resource ('Run OpenProof's website scan on one public web address') and enumerates the exact signals returned, so the agent knows precisely what the tool produces. It is clearly the only action tool among information-retrieval siblings, so differentiation is easy without opening a schema.

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?

Gives concrete invocation constraints: one public web address, send as its own request rather than inside a batch, and a per-client hourly rate limit. It does not explicitly contrast against any sibling by name, but the surrounding tools are all static DPDP reference lookups, so the usage context is unambiguous.

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