Attach to an engine you started yourself

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

With no annotations, the description carries the burden of disclosing behavior. It explains the connection to an already running engine, the binding to an instance number for other tools, and the default port behavior. It also mentions the prerequisite 'bridge-patched Zandronum' but does not describe error cases or side effects, which keeps it from a perfect score.

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 three concise sentences, each adding distinct information: action, usage condition, and default behavior. No redundant or filler content.

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?

For a tool with only two parameters and no output schema, the description provides sufficient context: purpose, usage condition, alternative tool, and default port. It could mention failure modes but is otherwise complete for its complexity.

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 provides no descriptions (0% coverage), so the description must compensate. It explains the instance parameter as 'bind it to an instance number for the other tools' and notes port 'Defaults to this instance's conventional port,' adding meaning beyond the bare schema types.

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 uses a specific verb 'Connect' and clarifies the resource: a bridge-patched Zandronum already running. It explicitly distinguishes from launch_instance by stating 'launch_instance binds automatically,' making its purpose unambiguous.

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?

It explicitly states when this tool is needed: 'Only needed for engines this session didn't launch: launch_instance binds automatically.' This provides a clear conditional for use and names the alternative tool, satisfying the when-to-use vs alternatives requirement.

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