Start streaming prices in the background

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

With no annotations, the description carries the transparency burden. It discloses that the subscription is standing/background, that nothing is pushed tick by tick, and that reads happen later via stream_quotes without consuming a REST rate-limit token. It does not mention how to cancel or whether resubscribing overwrites an existing stream, which is a moderate gap.

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?

Three sentences, front-loaded with the core action, then behavioral expectation and use case. Every sentence adds distinct value with 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?

The description covers the key invocation context, follow-up read path, and cost behavior despite having no output schema or annotations. It omits cancellation (stream_unsubscribe) and mode distinctions, but those are secondary to correct initial invocation.

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?

scripCodes is documented well in the schema, including example format and a pointer to search_instruments, but mode ('ltp' vs 'quote') has no semantic explanation in the schema or description. Schema description coverage is only 50%, and the description does not compensate for the undocumented mode parameter, leaving its meaning to inference.

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 uses a specific verb and resource: 'Open a standing subscription so prices keep updating in the background.' It clearly differentiates itself from stream_quotes by stating 'Nothing is returned tick by tick — call stream_quotes afterwards,' so an agent can tell what this tool does without opening the schema.

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?

It gives a concrete use case: 'Useful when the same names come up repeatedly in one conversation,' and tells the agent to use stream_quotes afterwards. It does not spell out when not to use it or compare with get_quotes/watch_prices, but the guidance is enough to route a typical call.

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