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

With no annotations, the description carries the burden. It adds the 'built-in' scope, indicating custom agent templates are not included, which is useful. However, it doesn't mention whether the result is cached, live, or anything about side effects, though 'list' strongly implies read-only behavior.

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?

A single, front-loaded sentence with no filler. The examples add useful detail without bloating the description.

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 zero-parameter list tool with no output schema, the description provides enough information to call the tool correctly and anticipate the result. A mention of the return format would be nice, but the verb 'List' and examples sufficiently convey the expected output.

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 tool takes zero parameters, and the schema confirms an empty object. The description compensates by explaining what will be listed, which is all that is needed. Baseline of 4 for no-parameter tools is appropriate.

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 states a specific verb ('List'), a clear resource ('Mainroom's built-in agent types'), and provides concrete examples (facilitator, timekeeper, etc.). This distinguishes it from sibling tools like join_meeting_as or send_demo_agent, which clearly perform different actions.

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 context is clear: use this tool when you need to know what built-in agent types are available. It doesn't explicitly compare against siblings, but none of the siblings are listing tools, so the appropriate use is implied. No exclusions are needed.

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