List EMQX Topics

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

Annotations already mark readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds valuable context that only topics with an active route (subscriber) are listed, and absence indicates zero subscriptions. This clarifies a non-obvious behavioral trait beyond the structured hints.

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 concise sentences deliver the core definition and a clarifying diagnostic note, with no filler. The description is front-loaded and every sentence 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 simple read-only list tool with an output schema and complete parameter documentation, the description explains the essential semantic (route = at least one subscriber) that the agent needs to interpret results correctly. It is complete and self-sufficient.

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?

All three parameters (page, limit, topic) are already fully described in the schema with defaults and constraints, so schema coverage is 100%. The description provides no additional parameter-level meaning beyond what the schema already documents, earning the baseline score.

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 defines the resource as 'topics that currently have a route' and equates that with 'at least one subscriber', making the tool's function clear. It builds on the title's verb 'List' to convey the exact scope and distinguishes it from related tools like subscription listing.

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 provides a diagnostic scenario: a topic missing means nobody is subscribed, which is a common reason messages vanish. This implies when to use the tool, though it doesn't explicitly name alternatives or exclude sibling tools.

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