Subscribe to live topic messages

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description doesn't need to restate those. It adds useful behavioral context: messages are written to a local sink directory, usable later via `path` in SourceFactory, and optionally creates a standing pipeline. This goes beyond the annotations without contradicting them.

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 a single, well-structured sentence that front-loads the core purpose ('use this tool to connect to a live data stream and subscribe to one or more topics'), then adds concise details on the sink and optional pipeline. 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?

Given the tool's complexity (7 params, no enums) and the presence of an output schema, the description covers the essential aspects: purpose, side effects, and optional configuration. It omits details on some parameters (host, port, type_, etc.) which the schema alone doesn't explain, but these are likely less central. The description is reasonably complete for an agent to know when and how to use it.

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?

The schema description coverage is 0%, so the description carries the full burden. It mentions 'one or more topics' (topics parameter) and 'pipeline config' (pipeline parameter), but does not explain host, port, type_, args, or overwrite. With 7 parameters and only 2 partially described, the description insufficiently compensates for the total lack of 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's purpose: 'connect to a live data stream and subscribe to one or more topics.' It specifies the verb (connect/subscribe) and the resource (live data stream topics), and differentiates from siblings like 'run_pipeline_batch' and 'query_messages' by focusing on live streaming and subscription.

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 opens with 'Use this tool to connect to a live data stream,' providing clear context for when to use it. It also explains that the sink directory can serve as input for other tools via SourceFactory, and mentions the optional pipeline for standing pipelines. However, it does not explicitly state when not to use it or name alternatives, though the context strongly implies it.

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