create_orderPlaces a live order in a Polymarket US market, letting you specify outcome, order type, price, quantity, and time in force to enter a trade that may use real funds.
LIVE ACCOUNT ACTION: Create a new order to enter into a market This operation may affect real funds or account state.
| Name | Required | Description | Default |
|---|---|---|---|
| body | Yes | Request to create a new order. |
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, readOnlyHint=false, idempotentHint=false, and openWorldHint=true, so the safety profile is largely covered. The description adds a real-funds/account-state consequence warning, which reinforces but does not extend that picture. It says nothing about blocking behavior with synchronousExecution, rejection semantics for participateDontInitiate, or irreversibility of a filled order.
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 highest-stakes information front-loaded in the leading clause. The missing sentence break between 'market' and 'This' is a minor blemish, and the brevity borders on under-specification for a tool this consequential.
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?
This is a high-complexity, real-money mutation with a deeply nested 15+ field request body and no output schema, yet the description covers none of it: no explanation of the order lifecycle, what is returned on acceptance vs rejection, or how synchronousExecution and maxBlockTime interact. For a destructive trading tool, the description is far thinner than the complexity demands.
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 description coverage is 100% and the nested body properties are documented in detail (intent vs outcomeSide+action, cashOrderQty for market orders, slippage ticks priority). The description adds no parameter meaning whatsoever beyond 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 ('Create a new order to enter into a market') and flags it as a live-account action, so the agent knows exactly what it does. It does not distinguish this from close siblings such as create_multiple_orders, preview_order, or close_position_order, so the agent must infer the boundary itself.
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?
The only guidance is the 'LIVE ACCOUNT ACTION' warning, which signals risk but not when to choose this tool over preview_order (dry run), create_multiple_orders (batch), or modify_order (amend). No exclusions, prerequisites, or alternatives are named despite several obvious siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.