publish_message

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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It indicates a publish operation (an outgoing side effect) but does not mention potential message loss semantics, delivery guarantees based on QoS, failure behavior, or whether the call returns an acknowledgment. This is a significant transparency gap for a mutation tool.

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 two sentences, front-loaded with the core purpose, and the second sentence adds necessary configuration context. Every word earns its place with no redundancy or 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?

Despite having an output schema, the description is incomplete for a tool with 3 parameters and an external side effect. It lacks parameter semantics and behavioral details, so an agent would not know how to craft a correct message or interpret QoS/retain values. The configuration note is helpful but insufficient for full operational understanding.

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%, and the description provides no information about the parameters (message, qos, retain). It does not explain what 'message' content should contain, what QoS values are accepted, or how retain behaves. The description adds zero value beyond the schema's bare property names.

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 clearly states the tool's action—'Publish a message to the configured MQTT topic'—with a specific verb and resource. This distinguishes it from the sibling tool get_mqtt_config, which retrieves configuration rather than sending data.

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 clear context by noting that broker connection settings are pre-configured via environment variables, so the agent understands no connection parameters are needed. However, it does not explicitly mention when to use this tool versus get_mqtt_config or any exclusion scenarios, so it falls short of a perfect score.

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