Send Message or Signal to PubNub Channel

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

With no annotations, the description carries full burden. It reveals that plain strings are auto-wrapped in a 'text' field, a useful detail. But it lacks disclosure of side effects (e.g., message delivery guarantees), error conditions, rate limits, or idempotency.

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: first states purpose and types, second adds key requirement and behavior nuance. No wasted words.

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?

Core behavior is covered: sending messages with key requirements and type differentiation. Missing details on response format or error handling, but given no output schema, the description is mostly adequate.

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 100%, so baseline is 3. Description adds value by explaining auto-wrapping of plain strings for the message parameter, and notes keys requirement beyond schema descriptions.

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 sends messages or signals to PubNub channels in real-time, and distinguishes between regular messages and lightweight signals. This differentiates it from sibling tools like get_pubnub_messages (retrieval) and subscribe_and_receive_pubnub_messages (receiving).

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 mentions the requirement for publish and subscribe keys and hints at obtaining them via manage_keysets tool. However, it does not specify when to use signals vs messages, nor does it exclude alternative tools for similar tasks.

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