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 so excellently. It discloses blocking behavior, polling interval, timeout handling, and the critical non-raising timeout behavior ('Never raises on timeout — returns satisfied: false + final hash'). This goes beyond the schema by explaining runtime behavior and result semantics.

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?

The description is two compact paragraphs: the first line states the purpose, and the second adds essential behavioral details. Every sentence contributes value—no filler, no repetition of schema fields. It is front-loaded with the main action.

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?

Given the tool's moderate complexity (5 params, nested target object) and the existence of an output schema, the description fully covers the key aspects: what it does, how it behaves (polling, timeout, return), and the edge case of loading screens/transient UI. It is sufficiently complete for an agent to select and invoke it 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 coverage is 100%, and each parameter already has a descriptive schema comment. The description adds context about interval/timeout ('handles loading screens and transient UI') but does not explain target structure or device semantics beyond what the schema provides. This aligns with the baseline 3 for high schema coverage.

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?

The description opens with a specific verb+resource: 'Block until a semantic target appears or disappears on screen.' This clearly distinguishes wait_for from siblings like verify_element (which likely checks current state) and locate (which finds an element), as it emphasizes blocking/polling over time.

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?

The description provides clear usage context: 'Polls fresh snapshots every interval seconds until the condition holds or timeout expires (handles loading screens and transient UI).' This implies when to use the tool (waiting for dynamic UI states) but does not explicitly name alternatives or exclusion cases, which would be needed for a 5.

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