Manage EMQX MQTT Users

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

Annotations already disclose readOnly=false and destructiveHint=true. The description adds valuable behavioral context: operations are limited to create/delete/read, and writes fail if no authenticator exists. It does not contradict annotations.

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?

The description is four sentences long, front-loaded with the main purpose, and every sentence earns its place: scope, clarification, prerequisite, and operations. No fluff or redundancy.

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?

Combined with detailed schema annotations and output schema, the description covers purpose, use case, prerequisite, and allowed operations. No critical gaps remain for a moderately complex CRUD tool.

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 five parameters have full schema descriptions (100% coverage), so baseline is 3. The description adds extra meaning to the operation parameter by explicitly enumerating allowed values (create, delete, read), which the schema description references.

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 names the specific resource (MQTT accounts in EMQX's built-in authentication database) and lists the operations (create, delete, read). It also distinguishes these credentials from dashboard logins, preventing confusion and differentiating from sibling tools like emqx_list_authn.

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 clearly states when to use this tool: for device credentials, not dashboard logins, and includes a necessary prerequisite—create an authenticator first. It does not explicitly name alternative tools or state when not to use it, but the context is strong.

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