solve_recaptcha_v2

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

Beyond the annotations (readOnlyHint=false, openWorldHint=true), the description discloses a non-obvious constraint (same session/address), the dual return path (token or taskId to poll via captcha_status), and that a human may be involved. It doesn't mention credits, rate limits, or timeouts, so it stops short of a 5.

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?

Three sentences, each load-bearing: what it does, when to use it (with the alternative), and what comes back. Front-loaded with the operation and inputs.

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 carries the return-value burden and does so ('the token, or a taskId to follow with captcha_status'). Combined with the session constraint and routing to solve_and_continue, an agent has everything needed to invoke and follow up correctly.

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 covereage is 100% and the schema already documents pageUrl and sitekey with source detail (data-sitekey attribute). The description names the same two inputs but adds nothing about the optional 'invisible' flag, so it only matches, not exceeds, the schema.

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 ('Solve a reCAPTCHA v2 challenge') plus the inputs (sitekey, pageUrl) and the artifact produced (gRecaptchaResponse token). It also names the sibling it must not be confused with (solve_and_continue), so an agent can separate them without opening any 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?

Explicit routing is given: 'Use only when you will submit the token yourself from the same session and address; to read the page behind the challenge use solve_and_continue.' This supplies both the inclusion condition and the named alternative.

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