iphone_wait_for

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: it discloses the return-on-match behavior, the timeout-error failure mode, and a non-obvious matching exclusion (text inside input fields is ignored). It omits what a successful match returns (the element, its identifier, a boolean) and whether the timeout failure is an exception versus a status value.

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?

A single front-loaded clause states the action, followed by parenthetical examples, then the return/timeout contract and the exclusion. No filler sentences; every clause (examples, immediate-return, timeout error, sibling replacement, input-field exclusion) carries distinct information.

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?

For a blocking-wait tool with no annotations and no output schema, the description should state what comes back on a successful match, since structured fields cannot. It covers timing, failure mode, and matching rules, but the return contract is left implicit ('出现就立即返回' — returns, but what?).

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 50% — only `timeout` is documented ('最多等几秒(不超过 30)'). The description compensates for the undocumented `text` parameter by defining it as a substring match against element text and excluding input-field content, which is meaningful added semantics. Baseline 3 for the schema gap balanced against that contribution.

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: wait for a UI element containing given text to appear, returning as soon as it does and erroring on timeout. The scope note ('input field text doesn't count') sharpens the target of the wait, and 'replaces repeated screenshot polling' distinguishes it from the iphone_screenshot/iphone_list_elements siblings without naming them explicitly.

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?

Gives concrete triggers ('page loaded', 'popup appeared') and an explicit alternative it supersedes ('代替反复截图轮询'), which routes the agent away from a screenshot-poll loop. It does not say when NOT to use it (e.g. for elements with no visible text, where iphone_list_elements would be the fallback), so it stops short of full when/when-not coverage.

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