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

Annotations already establish it as read-only, idempotent, non-destructive, and closed-world. The description adds substantial behavioral context beyond that: the 0-100 scale, neutral value of 50, up/down 10% thresholds, US-only scope, roughly 15-minute delay, and that it returns index and counts rather than prices.

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 are tightly front-loaded: the core metric and scale come first, then usage guidance, then scope and return limitations. Every sentence adds useful information without repetition.

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 and no parameters, the description carries the return-shape burden and does so by explaining that it returns the index and counts, not prices. It also supplies market scope and delay details needed to interpret the result 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 tool has zero parameters, so no parameter semantics are needed. The description does not introduce unnecessary parameter discussion, which is appropriate.

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 states a specific resource (today's StockFloc Heat Index) and what it returns (index plus hot/frozen stock counts), making the tool's function clear. It does not explicitly name or contrast with the sibling get_hot_stocks, though it partially differentiates by saying it returns counts rather than prices.

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 clear usage context: use when someone asks how hot or cold the stock market is today, or how many stocks made big moves. It does not explicitly state when not to use it or name the sibling alternative, so it is strong but not fully exhaustive.

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