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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description still adds real value beyond them by specifying the filtering ('active', authorized-for-this-connection) and that participant identities are included in the result — meaningful since no output schema exists. Pagination/ordering behavior remains undisclosed.

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 sentence that front-loads the action and scope with no filler. Nothing repeats the title verbatim or restates annotation flags.

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 tool with no output schema, the description conveys source of truth (connection authorization), filter (active), and returned content (rooms plus participant identities). Missing only result-shape specifics such as ordering, sizing, or how many rooms are returned, which an agent may want before calling.

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 the baseline is 4 and there is no parameter meaning for the description to carry. Each extra sentence on arguments would be waste here.

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?

States a specific verb and resource ('Returns active rooms') plus the key scoping qualifier 'authorized for this connection', which is the distinction an agent needs. It does not name or contrast with the many sibling listing tools (list_invites, list_files, room_situation), so sibling differentiation is left implicit.

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?

Usage is only implied: 'active' and 'authorized for this connection' hint at discovery/discovery-before-joining. There is no explicit statement of when to call this versus room_situation, catch_up, or list_invites, and no exclusions or prerequisites.

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