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

Annotations only supply readOnlyHint=true; the description adds genuine behavioral context beyond that: the 24h default window, the hard 168h cap, the 'Free' cost signal, and the exact shape of returned data including per-coin totals. Missing is any mention of result caps or pagination for large windows.

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?

A single dense sentence that front-loads the resource and window, then lists return fields in a scannable series, ending with the cost signal. No filler, and the most decision-relevant constraints come first.

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 correctly spends its words describing the return payload, which is the right call. The remaining gap is operational: no indication of how many fills are returned or whether large 168h queries are truncated.

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% and the undocumented parameter is precisely the one the description covers: 'hours' gets its default and 168h maximum stated in prose. The address and min_usd parameters are already documented in the schema, so the description complements rather than repeats.

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 names a specific verb+resource ('Recent Hyperliquid fills for a wallet') and enumerates the exact payload fields, so it is far from a tautology. It doesn't explicitly contrast with get_wallet_positions or start_wallet_alerts, but the resource noun makes the distinction inferable.

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 useful context (default 24h, max 168h, 'Free'), which implicitly tells the agent this is a cheap read for recent activity. However, there is no explicit statement of when to prefer this over get_wallet_positions or when to start alerts instead.

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