nex_browser_captcha_prepare

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

With no annotations, the description carries the full burden and does well: free/no purchase, which widget families are supported, that missing params or an uncaptured callback are hard blockers, and the 'never silently reload a filled form' safety rule. It stops short of describing what the capture returns or how long it waits, so not 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?

Front-loads the capture action and packs the routing rules into a small number of dense sentences with no filler. The opening 'Free, no purchase' framing is somewhat incidental to the action and every clause is compressed rather than structured, which costs a point.

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?

Adequate for a nested-object, zero-required-param tool with no output schema: it covers supported widget types, the grid escape hatch, blocking failure modes, and the next step. The main gap is that the return payload (availability/schema data) and the grid sub-field semantics are not described.

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 coverage is only 40%, and the description compensates only partially: it explains when to pass challengeId and that grid selectors plus mode are needed for non-reCAPTCHA grids. It never mentions pageId, sessionId, challengeUrl, or the required nested grid fields (root, tiles, instruction, verify, success), which are undocumented in both places.

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 concrete verb+resource ('capture the page CAPTCHA') and adds secondary outputs (product availability, online schema), which distinguishes it from siblings nex_browser_captcha_submit/complete/buy. The phrase 'check product availability and the online schema' is slightly ambiguous about what is actually returned, keeping it short of a 5.

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 names the alternatives and the conditions for choosing them: explicit reCAPTCHA v2/Turnstile, image grids, and the instruction not to fall back to GRID or nex_captcha_buy on missing params/403/timeout. It also gives an exclusion (canvas/custom widgets need a site adapter) and a hand-off rule ('When ready, call nex_browser_captcha_submit').

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