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

With no annotations, the description fully discloses effects: updates `seen` doc, clears badge count, removes from inbox. Explicitly marks as a WRITE operation with a warning about data mutation.

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?

Concise yet comprehensive: single line for endpoint/purpose, bullet points for access, idempotency, and warning. No fluff, every sentence adds value.

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?

Given simple input schema, no output schema, and no annotations, the description fully covers the action, access constraints, idempotency, and mutation details, making it complete for an agent to use.

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?

Only one parameter (roomID) with schema description 'Room ID'. The description adds no further meaning beyond the schema, which already has 100% coverage. Baseline score of 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?

The description explicitly states the tool unsubscribes from a room, listing the room types (public channel, discussion, quick-question, event). It distinguishes from siblings like rooms_subscribe_create (subscribe) and other room management tools.

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?

Clearly specifies when to use (caller must already be a subscriber) and when not to use (DMs and group DMs cannot be unsubscribed). Also mentions idempotency, providing guidance on repeated calls.

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