subscribe_news_firehose

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It usefully discloses the $0.10/day cost, <1 second latency, and that it returns a WebSocket URL, but it does not explain subscription lifecycle, cancellation, renewal, or what happens when the duration ends.

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 concise sentences that front-load the core purpose, then add cost and latency details. Every sentence earns its place with no 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?

With no output schema, the description should clarify the return value more precisely; it only says 'provides WebSocket URL.' It also omits authentication requirements, the structure of subscription metadata, and the format of messages delivered over the WebSocket, which are important for a subscription 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?

The input schema already provides complete descriptions for both parameters, including the enum for duration and the allowed source values. The description adds no further parameter-level detail, and its phrase 'from all sources' could be slightly confusing given the optional sources filter.

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 it subscribes to a real-time crypto news firehose and provides a WebSocket URL. This distinguishes it from one-off news retrieval tools like get_crypto_news or get_defi_news by emphasizing streaming delivery.

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 implies use for continuous low-latency news delivery via WebSocket, which differentiates it from query-based news tools. However, it does not explicitly state when not to use it or name alternative tools, leaving room for ambiguity.

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