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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: it clarifies that output varies by access level ('Keyless returns direction, share and coins; Starter adds the dollars') and labels the data as 'Descriptive market data only', which sets expectations about the non-account-specific nature of the response.

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 compact and front-loaded with the core purpose. The three sentences each add distinct value: scope+outputs, use cases, and access-tier behavior. The phrasing is slightly dense in the first sentence due to the colon-separated list, but it remains efficient and free of filler.

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 simple one-parameter tool with an output schema present, the description covers purpose, example questions, key output fields, and access-level behavior. It lacks an explicit note on how to interpret 'net direction' (e.g., bullish/bearish values), but the output schema likely covers return values, so no critical information is missing for an agent to use 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 documents the single window parameter with complete coverage, including its enum values and default, so the baseline is 3. The description references 'radar window' in context, which reinforces the schema meaning, but it does not provide additional semantic detail beyond what the schema already gives. No further compensation is needed given 100% schema coverage.

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 the tool's purpose with a specific verb context ('where whale money is moving between sectors') and enumerates the exact outputs (net direction, share of tagged flow, coins). It distinguishes itself from sibling tools like whale_flow by focusing on sector-level rotation, and lists concrete sector examples, making the scope unmistakable.

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 provides explicit example questions the tool answers ('which sectors are whales rotating into', 'is money leaving memes'), which communicates the intended use context clearly. It does not explicitly compare against alternatives or state when not to use it, but the sector-level framing is strong enough to guide an agent toward appropriate scenarios.

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