wait_change

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

Annotations cover the safety profile (readOnly, idempotent, non-destructive), and the description adds genuinely new behavior: timeout is not an error (ok=true, changed=false plus final snapshot), `exited` is true only on a detect_child_exit session whose child died, and hash is reusable as the next baseline.

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 one-line purpose, then layers usage, return shape, and edge cases in dense, purposeful sentences. No filler; every clause adds actionable 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?

No output schema exists, but the description enumerates the return fields ({ok, changed, hash, alive, exited, text, json}) and explains the non-obvious ones. Timeout, baseline, and exit semantics are all covered, so an agent can 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?

With 0% schema coverage the description must carry the burden; it fully explains baseline_hash (default = screen at call time, or a prior hash) and covers timeout semantics. It leaves sid and the timeout_ms unit/default unstated, but the non-obvious parameter is well documented.

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 ('Block until the screen content changes, then snapshot') and frames it as the 'did my action land?' primitive. It explicitly distinguishes itself from siblings by naming send_line/send_keys as the callers and wait_regex as the weaker alternative.

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 explicit when-to-use ('call it right after send_line/send_keys'), states the baseline default and how to override it, and names the alternative (wait_regex) with the condition that favors this tool ('Can't false-positive on text that was already on screen').

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