List available live topics

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. The description adds valuable behavioral context beyond that: it returns names 'without starting a persistent recording' and requires a reachable service, which informs the agent about network dependency and side-effect-free behavior.

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?

Three concise sentences, front-loaded with the core purpose. Every sentence earns its place: purpose, supported types, prerequisites, side-effect note, and alternative. No fluff.

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?

With an output schema present, return format isn't needed. The description covers purpose, type_ values, network requirements, and the alternative tool. It could elaborate on host/port defaults or pagination, but for a listing tool it's adequately complete.

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 0%, so the description must compensate. It lists supported type_ values explicitly ('mqtt, ros1.bridge, ros2.bridge') and mentions host/port defaults. However, the 'args' parameter is completely unexplained, and host/port are only vaguely referenced without format or default values.

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 states a specific verb ('Discover') and resource ('topic names from a live broker or ROS bridge') and clearly differentiates from siblings by noting 'before subscribing' and explicitly routing to 'describe_data_source for an existing recorded log'. An agent can immediately tell what this tool does and how it differs from similar 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?

The description gives clear context: use it before subscribing, requires a reachable service, and points to the alternative describe_data_source for recorded logs. It doesn't explicitly state when NOT to use it, but the alternative condition is clear enough.

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