Crank Protocol

lend_repay

Destructive

Repay borrowed amount (non-custodial). Returns an UNSIGNED base64 tx + current health factor. amount in base units of token. Past the daily free tier an x402 payment_header is required.

idempotency_key (optional): a client-generated UUID. Retrying with the same key + same args replays the original result instead of re-repaying. Reuse the SAME key across the build call and its signed_transaction completion call -- see lend_deposit; the two legs dedupe independently, so this never raises IDEMPOTENCY_CONFLICT.

signed_transaction / verify (two-phase execution): see lend_deposit -- re-call with the signed tx and Crank broadcasts it, confirms it on-chain, and re-reads the repaid balance + obligation health.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`token`	Yes
`amount`	Yes
`market`	No
`verify`	No
`protocol`	Yes
`caller_id`	No
`pay_in_crank`	No
`payment_header`	No
`wallet_address`	Yes
`idempotency_key`	No
`marginfi_account`	No
`signed_transaction`	No

Output Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedAug 11, 2026

addedInput schema / properties / signed_transaction

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null
+}

addedInput schema / properties / verify

Added value: +{
+  "default": true,
+  "type": "boolean"
+}

First observedJul 27, 2026

TDQS

A3.8/5.0

Behavior4/5

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

The description adds substantial behavior beyond the annotations: non-custodial may have an UNSIGNED transaction, specific idempotency replay semantics, and two-phase execution via signed_transaction. It does not exhaustively describe every effect, but it covers the most important behavioral traits and does not contradict the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-organized and front-leftloaded with the core purpose and immediate constraints. The two follow-up paragraphs are focused and each carries its own purpose, though the reference to lend_deposit could mean repeated reading for full context.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a complex a12-parameter tool with 0% schema coverage, the description covers key behavioral flows but omits too many parameter meanings and fails to explain how protocol/token/market/marginfi_account should be specified. The output schema and annotations provide some baseline, but an agent would still need to infer significant details.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 0% schema coverage, the description must compensate, and it partially does by explaining amount units, payment_header, idempotency_key, and signed_transaction/verify. But it does not describe core parameters like protocol, token, wallet_address, market, caller_id, or marginfi_account, leaving meaningful uncertainties for a 12-parameter tool.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb and resource: 'Repay borrowed amount (non-custodial).' It further clarifies the exact output ('UNSIGNED base64 tx + current health factor'), making it immediately clear that this is the repayment counterpart to lending tools like lend_borrow and lend_deposit.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives helpful operational context, such as when payment_header is required and how the two-phase signed_transaction flow works. However, it does not explicitly state when to use this tool versus lend_borrow or lend_deposit, or describe exclusions/alternatives. It mostly implies usage from the tool name and repay context.

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

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