Watch live prices for a fixed window

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

With no annotations provided, the description carries the burden of behavioral disclosure. It clearly discloses that the call blocks for the requested duration and that instruments not already subscribed are unsubscribed afterwards. This goes beyond a basic summary and gives the agent important execution-time and side-effect awareness.

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 three short sentences with no wasted words. It front-loads the core behavior, then adds a critical blocking warning and a cleanup guarantee. Each sentence earns its place.

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 lack of an output schema and annotations, the description covers the essential operational behavior: subscription, collection window, blocking, cleanup, and summary fields. It could be slightly more explicit about the exact returned series shape, but overall it is complete enough for an agent to invoke the tool correctly.

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 documents all four parameters with 100% coverage, so the baseline is 3. The description adds useful context around seconds (blocking) and the summary output, but it does not need to repeat parameter meanings already present in the schema.

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 a specific action sequence: subscribe to the live price feed, collect ticks for a duration, then return a series with per-instrument summary fields. It also differentiates this tool from the sibling stream_* tools by emphasizing the fixed-window, one-shot nature and the cleanup behavior.

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 gives useful context, such as 'This blocks for the requested duration, so keep it short,' and explains the unsubscribe behavior. However, it does not explicitly state when to choose this tool over stream_subscribe, stream_quotes, or get_quotes, so usage guidance is implied rather than explicit.

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