create_conversionExecutes a preview_conversion quote before it expires to complete a crypto conversion; the balance updates immediately, and re-calling returns the same conversion.
Step 2: executes a preview_conversion quote before its expires_at; the balance changes at once. A preview runs once — calling again returns the same conversion.
| Name | Required | Description | Default |
|---|---|---|---|
| preview_id | Yes | preview_id from preview_conversion. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds substantial behavior beyond the annotations: it names the prerequisite preview_conversion quote, the expires_at timing constraint, the immediate balance change, and the idempotent behavior of returning the same conversion on repeat calls. These details are consistent with the destructive and idempotent hints.
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?
The description is two tight sentences, front-loaded with the step and action, and every clause adds operational meaning without repetition.
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 mutation tool with rich annotations, the description covers the prerequisite, timing, side effect, and idempotent behavior. An agent has enough information to invoke it correctly without needing 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 already 100%, including the preview_id description. The tool description adds only the expiry constraint on the preview quote, which is useful but does not go much beyond what the schema already documents for the single parameter.
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 states a specific verb and resource: it executes a preview_conversion quote. It also frames the operation as 'Step 2', which clearly distinguishes it from the sibling preview_conversion step.
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 clearly says this is the execution step for a preview_conversion quote and must happen before expires_at, which gives strong usage context. It does not explicitly state exclusions or failure behavior if the quote has expired, so it falls just short of fully explicit when/when-not guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.