unity_select_instance

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

No annotations provided, so description carries full burden. It explains the session-level effect and routing behavior clearly. However, it doesn't mention if selecting a different instance automatically deselects the previous one or if there's a way to unselect. Still, for the context, it's very transparent.

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?

Description is three sentences, each with important information. The first sentence states the core purpose, the second gives prerequisite, the third addresses parallel safety. Slightly verbose but all relevant.

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 simple schema (one required parameter) and no output schema, the description covers the essential behavioral context. It could mention what happens if an invalid port is provided, but that's minor.

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 100% and the description adds extra context about where to get the port value and that it's required. This adds value beyond the schema.

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 selects a Unity Editor instance for the session, and explains that subsequent commands will be routed to it. This differentiates it from unity_list_instances which lists instances, and other sibling tools that perform actions but don't set routing context.

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?

Explicitly instructs to call unity_list_instances first, provides the source for the port, and gives parallel safety guidance for multi-agent scenarios. This is comprehensive usage guidance.

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