pir_pick_region

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

No annotations are provided, so the description carries the full burden. It discloses that the tool blocks until completion or timeout, can be cancelled with Escape, and returns the geometry. It doesn't mention whether the picked region is stored for later use, but the core interactive and blocking traits are clear.

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?

Three sentences, no filler, with the core behavior front-loaded and the usage guidance and blocking behavior included. Every sentence 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?

The description is largely sufficient for knowing what the tool does and how it behaves, but it omits what 'name' is for, which is a required parameter. Without annotations or an output schema, that gap keeps the definition at minimum viable rather than fully complete.

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 only 50%: the required 'name' parameter has no schema description and the tool description does not clarify it. The optional 'purpose' is documented in the schema, but the description adds no meaning for the parameters, so it fails to compensate for the uncovered one.

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 clearly states a specific action: ask the person at the screen to draw a rectangle to watch. It distinguishes itself from pir_define_region by explaining the human-in-the-loop interaction and explicitly calling out that 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?

The description gives an explicit usage rule: prefer this over pir_define_region whenever a human is present. It also explains the UX outcome and blocking behavior, so an agent knows when this tool is the right choice.

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