solve_captcha

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

With no annotations, the description carries full burden. It discloses that the tool calls an external API, returns a solved token, and can inject the token into a form field via inject_selector. It does not mention rate limits or failure modes, but provides sufficient behavioral context.

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 very concise at two sentences plus a bullet list. It front-loads the primary purpose and uses a clear structure for enumerating kinds. Every sentence adds value without redundancy.

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 has 6 parameters and an output schema, the description is somewhat complete but lacks explanations for some parameters. It covers the core functionality and injection behavior, but the parameters website_url and website_key are undocumented. The output schema exists, so return value explanation is not needed.

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 0%, so the description must compensate. It explains the 'kind' enum and mentions api_key and inject_selector, but does not describe the required parameters website_url and website_key, nor the optional action parameter. This leaves significant gaps.

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 it solves a CAPTCHA via CapSolver HTTP API and lists the supported CAPTCHA kinds (turnstile, recaptcha_v2, recaptcha_v3, hcaptcha). It differentiates from siblings like solve_recaptcha_ai by specifying the CapSolver API and detailing injection behavior.

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 explicitly mentions the prerequisite: needing CAPSOLVER_KEY env var or passing api_key. It implies usage for solving CAPTCHAs, but does not explicitly state when not to use or compare to alternatives.

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