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

With no annotations, the description carries the behavioral burden. It discloses that archived rooms are read-only, that membership is per-room via the same connection, and that there is no active-room switch. It does not mention pagination or error behavior, but for a list operation the disclosed traits are substantive and accurate.

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 front-loaded with the main action and resource, and the second sentence delivers important membership context without filler. The second sentence is dense and semicolon-heavy, but every clause earns its place.

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 simple list tool with one optional fully-documented parameter, the description covers scope, membership requirements, archived read-only rooms, and the no-switch behavior. The lack of an output schema is not a major gap because the description already mentions the archived flag, though a fuller return-format note would help.

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 description coverage is 100%, and the schema fully documents the optional connection parameter. The description adds no new parameter-level meaning beyond saying 'same connection,' so baseline 3 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?

Description uses a specific verb ('List') and a specific resource ('your joined rooms in this workspace and your private memory vault'), including archived read-only rooms. This clearly distinguishes the tool from room creation/join siblings.

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 that membership must already be granted, that the same connection is used, and that there is no active-room switch. It does not explicitly name alternative tools or when-not-to-use conditions, but the context is clear enough for an agent to select it correctly.

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