verify_cf

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

With no annotations, the description fully discloses behavior: uses OpenCV template matching to locate and click the checkbox, uses a default image if none provided. It also notes limitations (simple CF only), providing transparency beyond the schema.

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 concise (four sentences), front-loads the main purpose, then details the method, parameter, and usage guidance. No unnecessary information.

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 tool's complexity (CF challenge verification), the description covers the mechanism, parameter, limitations, and companion tools. The presence of an output schema handles return values, so completeness is high.

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 only parameter, template_image, is described in context: it's a path to a cropped image, with the fallback to an English default. This adds value beyond the schema, which has 0% coverage.

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 verifies Cloudflare challenges using nodriver's built-in method, with specific details about template matching and clicking Turnstile. It distinguishes from siblings like click_turnstile by mentioning simple vs managed-mode, making its purpose unambiguous.

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?

Explicitly states when to use (simple CF interstitials) and when not (managed-mode Turnstile), with recommendations to combine with storage_state or solve_captcha for advanced cases. The template_image parameter is also explained.

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