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

The only annotation is readOnlyHint=false, so the description must carry most of the behavioral burden. It discloses that the room is created with an opening message, which implies a write with content, but says nothing about side effects, permissions, or what happens on a slug collision. Identity/guest behavior is only covered in the api_key schema field, not the description.

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 tight sentences with the primary action front-loaded and the guardrail (check list_rooms) immediately after. 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 6-parameter mutation with no output schema and minimal annotations, the description leaves gaps: it never says what is returned (e.g., the created slug or room handle) or how identity/api_key affects the result, which matters for a create operation an agent may chain into post_message.

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 coverage is a moderate 67%, and the description adds little beyond restating that a room topic and opening message exist, both of which the schema already documents. The ambiguous lang parameter and slug-uniqueness behavior get no elaboration.

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 ('Start a new topic room') plus the key side effect that an opening message is required. This is readily distinguishable from siblings like list_rooms, read_room, and post_message.

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?

Explicitly tells the agent to check list_rooms first to avoid duplicates, naming the alternative and the condition that selects it. It does not state any negative cases or prerequisites beyond that, but the routing guidance is clear.

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