start_session

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

With no annotations, the description carries full burden. It discloses starting a display, launching an application, dismissing dialogs, and returning a status string. It hints at state creation (must be called first) but lacks details on idempotency or resource cleanup. Overall adequate.

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 concise sentences cover the core action, usage prerequisite, dialog handling, and return value. Every sentence is purposeful with no redundancy.

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 role as a session initializer and the presence of an output schema, the description covers key aspects: what it does, when to call it, and what it returns. Lacks mention of environment prerequisites or behavior on repeated calls, but sufficient for most use cases.

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 description adds no explanation of the parameters (width, height, display), despite 0% schema description coverage. The parameters are self-explanatory, but the tool definition does not help the agent understand how to configure them beyond defaults.

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 tool's purpose: starting a private Xvfb display with openbox and launching OrcaSlicer. It uses a specific verb-resource combination and distinguishes itself from siblings by indicating it must be called before any other tool.

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 explicitly states the tool must be called before any other tool, providing clear when-to-use guidance. It does not list explicit when-not-to-use scenarios or alternatives, but the context implies it is the initial setup step.

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