Wait for Parallels guest readiness

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

Annotations declare readOnlyHint=true and idempotentHint=true, so the description correctly adds the blocking/polling behavior ('Poll the guest OS') without contradiction. It also gives a concrete readiness condition ('Parallels Tools and execution answering'), which adds value beyond annotations. However, it does not explain timeout behavior (what happens if the guest never becomes ready), which is a minor gap given the annotations already signal safety.

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 a single sentence with no filler, front-loading the action ('Poll the guest OS'). It is concise but the phrase 'and execution answering' is awkward and could be clearer, though it does not add unnecessary length. Overall it is well-structured for a short description.

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 waiting tool, the description fails to explain critical behavior: what happens on timeout (does it return, raise an error?), whether it returns immediately if already ready, and the exact meaning of 'execution answering'. The output schema may define return values, but the timeout behavior is a key side effect that is unaddressed. Given the tool's purpose, this is a significant omission.

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 description coverage is 0%, so the description must explain the parameters, but it does not. It references the 'guest OS' but never explicitly states that 'vm' is the identifier or how to specify it, and it gives no meaning to 'timeout_s' beyond its name and default value. The agent must rely on parameter names and defaults, which is insufficient for parameters not self-explanatory (especially timeout_s semantics).

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 states a specific verb ('Poll') and resource ('guest OS') with a clear goal ('until Parallels Tools and execution answering'), and the title reinforces the intent. It is distinct from siblings like vm_status (which likely just reports state) and vm_exec (which runs commands), but it does not explicitly differentiate itself by naming alternatives.

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 gives no guidance on when to use this tool versus alternatives. It does not mention that it should typically be used after starting a VM, nor does it suggest using vm_status for a one-shot readiness check instead of a blocking wait. The lack of any usage context leaves the agent to infer when to invoke it.

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