capskip-mcp

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Solve Friendly Captcha

capskip_solve_friendly_captcha

Solve Friendly Captcha proof-of-work challenges by sending the sitekey and page URL. Specify the protocol version or module script to ensure the site accepts the token.

Instructions

Solve a Friendly Captcha proof-of-work challenge. Nothing is shown on screen — the widget does arithmetic instead of asking the visitor to do anything. IMPORTANT: two entirely different protocols ship under this one name, sharing a brand and a sitekey namespace and nothing else, and a sitekey does not tell you which a site uses. Send version (v1 or v2), or send module_script and let CapSkip read the version off the build the site loads. Solving the wrong one returns a well-formed token the site rejects, with nothing to indicate the version was the problem. The form field also differs by version: v1 uses 'frc-captcha-solution', v2 uses 'frc-captcha-response'. Solve time is not a constant — the service sets the difficulty per request — so budget for that rather than assuming a fixed duration.

Input Schema

TableJSON Schema

Name	Required	Description
`url`	Yes	Full URL of the page the captcha appears on, including scheme.
`proxy`	No	Solve from this network. Worth setting sooner here than almost anywhere else: the service raises the difficulty for addresses it has already seen a lot of.
`sitekey`	Yes	The data-sitekey attribute of the widget element — the one carrying class='frc-captcha'.
`timeout`	No	Seconds to wait before giving up. Maximum 600.
`version`	No	The protocol version the site uses. Two entirely different protocols ship under this one name and a sitekey does not say which, so send this or module_script. Defaults to v1 when neither is given.
`api_server`	No	The data-residency tenant the sitekey belongs to: 'global' (the default), 'eu', or a full URL. Both tenants mint a token for the same sitekey, so the wrong one is only caught by the site's own check.
`module_script`	No	The src of the widget script tag carrying type='module'. The most reliable version signal there is, because it is the build the site actually loads: 'widget.module.min.js' means v1, 'site.min.js' v2.
`nomodule_script`	No	The src of the widget script tag carrying 'nomodule'. Read for the same reason.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`code`	Yes
`token`	Yes
`captchaId`	Yes
`solveSeconds`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Addedv1.2.0Sep 24, 2026

TDQS

A4.7/5.0

Behavior5/5

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

Annotations only declare readOnly=false, openWorld=true, and destructive=false, so the description carries the burden of behavioral disclosure. It adds substantial context: nothing is shown on screen, two unrelated protocols share the name and sitekey namespace, a wrong solution returns a well-formed but rejected token with no diagnostic, the form field differs by version, and solve time is not constant. This goes far beyond the structured annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is information-dense with no filler. It front-loads the core purpose, then adds the critical protocol warning, version-selection guidance, field-name differences, and latency caveat in a logical order. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the 8-parameter complexity, nested proxy object, enums, and output schema, the description plus schema together cover protocol selection, failure modes, version-specific form fields, and variable solve time. There is no critical missing context for an agent to invoke this tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with rich parameter descriptions, so a baseline of 3 applies. The description adds extra operational meaning beyond the schema by explaining how to choose between version and module_script, why sitekey alone is not a reliable version signal, and which form field names correspond to each version.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description begins with a specific verb, resource, and type: 'Solve a Friendly Captcha proof-of-work challenge.' It also clarifies the unusual v1/v2 protocol split, which distinguishes this tool from the sibling captcha solvers without relying on the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly tells the agent to send version or module_script, warns that solving the wrong protocol produces a token the site rejects, and notes that difficulty varies per request. It does not name sibling alternatives for exclusion, but the captcha-family context and protocol-specific guidance are strong enough to guide correct invocation.

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

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