computer_open

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

With no annotations, the description bears full responsibility for behavioral disclosure. It mentions 'with the default application', which is a behavioral detail, but it does not describe error handling, whether the call blocks, what side effects occur (e.g., opening a new window), or the nature of the response. For a tool that could fail if the target is invalid, this is a notable gap.

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, concise sentence that states the action and resource immediately. There is no filler, and it is front-loaded. It is appropriately sized for a tool with one parameter.

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 tool is simple (one parameter) and has an output schema, so return values are already documented. The description covers the core behavior and the target type. It does not explicitly differentiate from computer_launch_app, but the purpose clarity largely compensates. It is adequately complete for an agent to understand when to use it, though it could mention edge cases (e.g., invalid path).

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 schema already describes 'target' as 'File path or URL to open', and the description repeats this without adding new meaning (e.g., path format, URL schemes, or examples). Since schema coverage is 100%, the description adds no extra semantic value beyond the schema, so a baseline of 3 is appropriate.

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 the action ('Open') and the resource ('a file or URL') with the qualifier 'with the default application'. This is specific and distinct from siblings like computer_launch_app (which would launch an app) and computer_click (which interacts with UI). It leaves no ambiguity about the tool's function.

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 does not explicitly mention when to use this tool versus alternatives. There is no reference to computer_launch_app or any other sibling, and no exclusionary guidance. The intended usage is implied by the purpose, but it does not proactively steer an agent away from other similar tools, leaving some inference required.

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