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

Goes well beyond the readOnly/idempotent annotations: it explains wallet resolution (main_wallet, agent_wallet, alias), truncation semantics (2000-fill page, hip3_truncated_dexes), partial-failure flags (hip3_complete, hip3_failed_dexes), the 90-day window cap, and a 30-calls/minute rate limit.

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 core identity before drilling into wallet/return-detail mechanics, and every clause carries real information. It is dense as one block paragraph, so slightly harder to scan than it could be.

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, the description shoulder the burden and does so fully—it documents the return structure (address, fills, hip3_fills, per-fill fields like coin, px, sz, side, closedPnl, fee, oid, hash) and failure signaling. An agent has everything needed to call and interpret it.

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 100% so the baseline is 3, but the description adds constraints the schema does not state: a 90-day maximum window and that end_time cannot be in the future. It also restates the 24h default, which is redundant with the schema.

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?

States a specific verb and resource ('YOUR Hyperliquid fills (executed trades)') and disambiguates from sibling tools like get_open_orders and get_positions by scoping to executed fills. The 'my fills today' framing makes the intent 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?

Provides clear usage context via the phrase 'the call for "my fills today"' and directs narrowing the window on truncation. However, it never names alternatives (e.g., get_open_orders for open orders vs. get_positions) so the agent must infer that this is the executed-trades tool.

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