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

Beyond annotations (readOnly/idempotent/openWorld), the description discloses key behavioral facts: the premium/pay-per-call access model with the exact onboarding tool, the 10,000-most-recent-fills cap, and the `historyTruncated` signal that flags when the window was cut short for active wallets. This is exactly the operational context annotations cannot express.

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?

Front-loaded with the access-model tag in brackets, then the capability summary, then the truncation caveat. Dense but every sentence earns its place; the metric enumeration is long yet informative rather than filler. Minor redundancy between the bracketed premium notice and the disclaimer keeps it from a 5.

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 read-only analytics tool with an output schema, the description is complete: it covers purpose, access prerequisites, data-window limitations with a truncation indicator, and scope disclaimers. Return value structure is handled by the output schema, so no detail is missing that an agent needs to call this 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?

Schema coverage is 67%; `address` and `curvePoints` are documented in the schema, while `lookbackDays` lacks a schema description. The prose compensates by explaining that lookback is measured in days and interacts with the 10,000-fill cap, adding genuine meaning beyond the schema for the undocumented parameter.

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 verb and resource ('Behavioral report for any wallet from its fills') and enumerates concrete outputs: winrate, average R, realized PnL, PnL curve, holding-time style, fees, most-traded coins. This clearly distinguishes it from siblings like hl_get_account (account state) or hl_smart_money_score (abstract score) without opening a 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 states an explicit prerequisite ('needs an API key: call hl_request_free_key first, or pay per call via x402') and defines the analysis basis ('from fills') and scope ('Analytics only, not investment advice'). It does not explicitly contrast with sibling analytical tools such as hl_smart_money_score or hl_portfolio_risk, so no exclusions are given.

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