launch_app

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

With no annotations, the description fully carries the burden. It details Xephyr display creation, Chromium special flags and CDP port, D-Bus isolation, return structure, failure conditions, and cursor separation for parallel agents.

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?

Well-structured with front-loaded purpose and separate details. Slightly verbose with some redundancy (Xephyr mentioned twice), but every sentence adds value. Could be trimmed slightly without losing clarity.

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 complexity (isolated display launch, parallel agents), the description is comprehensive. It explains return fields, failure modes, and usage caveats. The existing output schema is described in detail, so no gaps remain.

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%, but the description thoroughly explains each parameter: 'command' is any shell command with examples, 'name' is optional with default empty, 'size' defaults to '1440x900'. This compensates fully for missing schema descriptions.

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 verb 'Launch', the resource 'GUI app in its OWN new Xephyr display/window', and the output 'return its instance id'. It effectively distinguishes from sibling tools like open_file (for files) and close_instance (for managing instances).

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?

Provides concrete command examples, special handling for Chromium and other GTK apps, and warns against sharing instances between agents. Lacks explicit 'when not to use' direction, but context strongly implies it's for launching new app instances.

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