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

readOnlyHint=true and openWorldHint=false already establish the safe, non-mutating, closed-world profile. The description adds a genuine credential requirement ('Requires the organization API key'), which is useful context beyond the annotations, but says nothing about result ordering, pagination, or volume. With annotations carrying the safety profile, a 3 is appropriate.

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?

Two terse sentences with no filler, and the scope statement is front-loaded ahead of the credential note. Nothing is wasted, though the brevity leaves the entry a little thin.

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-argument, read-only listing tool with annotations already declaring the safety profile, the description covers identity, scope, and authentication — the essentials for correct invocation. Only minor gaps remain (no note about return shape or pagination), which are low-stakes for a list operation and no output schema is declared.

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, so there is nothing for the description to clarify; the baseline for an empty schema is 4. No parameter details are needed or missing.

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?

Clearly identifies the resource (rooms) and the scope (those your organization owns or joined), which distinguishes it from room_info, room_open, room_close, and room_transcript. The verb 'list' comes from the name and title rather than the body text, so it is clear but not fully self-contained.

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 phrase 'Rooms your organization owns or joined' implies the appropriate scenario (enumerating rooms) but never states when to prefer this over room_info for a single room or how it relates to the other room_* tools. Usage is implied rather than prescribed.

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