Each tool targets a distinct concern: two account-metric reads (threads vs. balance), one capability-discovery call, and one solve action. The descriptions make clear what each returns (working_threads/free_threads vs. monetary balance), and solve_captcha is unmistakably the only action tool. No two tools can plausibly be swapped.

All four names follow a strict verb_noun snake_case pattern: get_threads, get_balance, get_supported_captchas, solve_captcha. The get_* reads and the solve_* action are predictable, and a new tool would obviously be named by the same convention.

Four tools is a tight, purposeful surface for a narrow service (discover types, solve, check capacity, check balance). It is at the low end of the comfortable 3-15 range, and a small amount of padding (e.g., a combined account-status or error-lookup tool) would round it out, but nothing here feels redundant.

The core lifecycle is covered: get_supported_captchas to discover required args, then solve_captcha, with get_threads/get_balance for capacity and billing. Minor gaps exist around failure handling — no way to poll/retrieve a timed-out or asynchronous solve, and no reporting of failed solves — but the primary workflow has no dead ends.