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

With no annotations at all, the description carries the full behavioral burden. It discloses the per-call cost, that only derived signals are returned rather than raw notional/price data, and the payment/authorization mechanisms. It does not cover failure modes or response details, but the most consequential behaviors—cost, auth, and data scope—are transparent.

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 core semantics are front-loaded in the first sentence, with the example and bucket explanation following in a logical order. The payment/auth block is lengthy but necessary because there are no annotations providing this critical invocation information. The description is somewhat dense but each section 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?

For a tool with two optional parameters and no output schema, the description provides the output field names, an example, and billing/payment context, which is reasonably complete. The main gaps are that the limit parameter is undocumented and the value ranges for direction, strength, and confidence are not specified, leaving some ambiguity in interpreting the response.

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 has 0% description coverage, so the description must compensate. It does explain the hours parameter by noting 'Lookback ?hours= (default 48)', which adds real meaning. However, the limit parameter is never mentioned, leaving its semantics entirely to the schema, so coverage is incomplete.

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 that the tool returns 'recent dark-pool prints as derived signals' and lists the specific fields: symbol, direction, strength, confidence, size_bucket, with a concrete example. It is specific about verb and resource, but it does not explicitly distinguish itself from sibling tools such as get_institutional_moves.

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 usage when one needs dark-pool-derived signals and explains that the buckets 'flag institutional-scale accumulation or distribution,' providing useful context. However, it never explicitly states when to prefer this tool over alternatives or what situations make it inappropriate.

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