cancel_orderCancels an open limit order by its ID, such as ORD-3; filled orders cannot be cancelled.
Cancel an open limit order by its id, for example ORD-3. Filled orders cannot be cancelled.
| Name | Required | Description | Default |
|---|---|---|---|
| order_id | Yes | Order id from get_orders or place_order, for example ORD-3. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation risk is covered structurally. The description adds the useful eligibility rule about filled orders, but says nothing about side effects such as fund release, partial fills, or what confirmation is returned.
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?
Two short sentences with the core action first and the constraint second; no filler and nothing buried.
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 single-required-parameter mutation with no output schema and full annotation coverage, the description covers the operation and its key eligibility constraint. Only the post-cancellation outcome is left unstated, which is minor here.
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% and the schema already documents order_id with its source (get_orders or place_order) and the ORD-3 example. The description's mention of the id and example duplicates rather than extends the schema, so the baseline 3 applies.
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 ('Cancel an open limit order') with a scope qualifier that separates it from the read/place/preview siblings. It does not name a sibling explicitly, but the action is unambiguous against get_orders and place_order.
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?
Gives a clear precondition (order must be open) and an explicit exclusion ('Filled orders cannot be cancelled'), which is the main failure mode for this call. No alternative tool is named, though no sibling offers cancellation, so nothing critical is omitted.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.