solve_hcaptcha

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

Annotations only declare readOnlyHint=false and openWorldHint=true, so the description usefully adds the session/address constraint and the dual-mode behavior: it may return immediately with a token or return a taskId for a human-solved flow polled via captcha_status. It stops short of stating timeouts, cost, or failure modes, so it is strong but not exhaustive.

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 tight sentences with no filler: purpose first, then the routing constraint with its alternative, then the return shape. Every clause carries decision-relevant information and the discriminating constraint is front-loaded.

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?

There is no output schema, so the description assumes the burden of describing returns and does so (token, or a taskId to follow with captcha_status). Combined with the documented required params and sibling routing, an agent has everything needed to invoke this 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 description coverage is 100% and both required parameters are documented in-schema (sitekey from the data-sitekey attribute, pageUrl the page the widget is on). The description merely references the same two inputs by name and adds no format or constraint detail beyond the schema, so baseline 3 applies.

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 an hCaptcha challenge") plus the two inputs it consumes and the artifact it produces (the token). It also names the sibling it is not (solve_and_continue), so an agent can distinguish it from the adjacent captcha tools 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?

Explicitly narrows the use case ("Use only when you will submit the token yourself from the same session and address") and gives the alternative plus its selecting condition ("to read the page behind the challenge use solve_and_continue"). It further routes the async case to captcha_status.

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