Identify this agent's own window (PID lock)

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

Annotations are absent, so the description carries the full burden. It discloses the mechanism (PID ancestry) and the outcome (report the window), but does not describe the return format, potential failure modes, or whether the operation is strictly read-only. The description offers some insight but leaves gaps that could matter for correct consumption.

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?

Two sentences, no filler. The core action is front-loaded, followed by the purpose. Every word earns its place.

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 simplicity (no params, no output schema), the description covers the purpose, method, and use case well. The only notable omission is the exact output type (e.g., window ID string, numeric PID, or object), which could confuse an agent expecting a specific format, but this is a minor gap for a self-identification tool.

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?

The tool has zero parameters and an empty schema. The baseline is 4 for no parameters, and the description correctly does not add parametric details. There is nothing to compensate for.

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 ('Resolve and report') and resource ('the terminal window this agent is running in'), and explains the method (walking PID ancestry). It clearly distinguishes from sibling window tools that operate on arbitrary windows, not the agent's own identity.

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?

It explicitly identifies the use case: 'locks our identity for tools that move/resize us.' This tells the agent when to invoke it. However, it doesn't mention alternatives or when not to use it, but for a zero-parameter utility the guidance is adequate.

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