unity_select_instance

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

With no annotations provided, the description carries the full burden. It discloses that selecting affects subsequent calls and that port can change across restarts, but does not mention side effects like overriding previous selections or error states if the instance is not found. The parallel safety tip adds useful context.

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 two sentences plus a concise parallel safety note, all front-loaded. Every sentence serves a distinct purpose: stating the tool's role, identifying methods, and a critical safety warning. No unnecessary words.

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 no output schema and no annotations, the description adequately explains the tool's impact on subsequent calls but lacks details on return values, error handling, or prerequisites (e.g., using unity_list_instances first). The large sibling set implies dependencies that are not explicitly addressed.

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% with both parameters described. The description adds value by clarifying the stability contrast ('projectName stable, port dynamic'), which is implied but not as explicitly stated in the schema descriptions. This helps agents choose between the two identifiers.

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 that 'Select the Unity Editor instance this session targets; subsequent unity_* calls route there.' It uses the specific verb 'Select' and resource 'Unity Editor instance', and distinguishes this selector from sibling tools like unity_list_instances which list 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?

The description explains the two identification methods (projectName stable, port dynamic) and includes a parallel safety note advising to include port on every unity_* call when multiple agents share the process. However, it does not explicitly state when to use this tool versus alternatives or mention prerequisites like calling unity_list_instances first.

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