Use this when the user asks to cancel a resting or trigger order by its oid (from get_my_open_orders).
| Name | Required | Description | Default |
|---|---|---|---|
| order_id | Yes | The Hyperliquid order id (oid) to cancel — see get_my_open_orders |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already provide destructiveHint=true, readOnlyHint=false, and idempotentHint=false. The description adds that the cancellation applies to resting/trigger orders and that the oid comes from get_my_open_orders, but doesn't elaborate on side effects, reversibility, or failure modes beyond what annotations imply.
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, well-structured sentence that front-loads the trigger condition and includes the necessary identifier provenance. No wasted words.
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 one-parameter cancellation tool with strong annotations and a clear description, this is essentially complete. It could mention what the response or result looks like, but that's not required given the simplicity and the lack of an output schema.
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 schema fully documents order_id. The description's reference to get_my_open_orders for obtaining the oid adds slight context but is essentially echoed in the schema description, providing no meaningful extra semantics.
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 uses a specific verb ('cancel'), identifies the resource ('resting or trigger order'), and specifies the identifier source ('by its oid from get_my_open_orders'). This clearly distinguishes it from sibling tools like place_order, close_position, and set_position_tp_sl.
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 explicitly states when to use this tool ('Use this when the user asks to cancel...'), which is clear context. However, it doesn't enumerate when-not-to-use scenarios or explicitly name alternatives, so it stops short of a full 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct resource or action, but get_markets and get_price overlap in the data they return (price, 24h change, volume, funding), differing mainly by all-markets vs single-coin scope. The descriptions are explicit enough that an agent should rarely misselect, though the boundary is slightly blurry.
All tool names follow a consistent verb_noun snake_case pattern: get_ for reads, plus clear action verbs like place_, preview_, cancel_, close_, and set_. There is no mixing of styles or vague generic verbs.
13 tools is well within the ideal range for a trading-focused server. Each tool covers a distinct part of the workflow without feeling bloated or redundant.
The tool surface covers the full trading lifecycle: market data, account/position/order/trade reads, order preview and placement, cancellation, position closing, and TP/SL management. No obvious dead-ends or missing core operations for the stated Hyperliquid perp trading purpose.