# approve_jst_for_voting

Approve JST token for the WJST voting contract. Required before depositing JST to get voting power.

Agent View of the PolicyLayer registry record for `approve_jst_for_voting`. HTML page: https://policylayer.com/tools/justlend-mcp-server-justlend/approve-jst-for-voting

## Facts

- Tool: `approve_jst_for_voting`
- Server: Justlend (`justlend/mcp-server-justlend`) — https://policylayer.com/tools/justlend-mcp-server-justlend.md
- Homepage: https://github.com/justlend/mcp-server-justlend
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "approve_jst_for_voting",
    "arguments": {}
  }
}
```

## Why approve_jst_for_voting is rated Medium

This tool approves a spender (WJST voting contract) to transfer JST tokens on behalf of the caller. Token approvals are Write operations—they create or modify authorization state reversibly. While the caller can later revoke or adjust the approval, misuse could allow an AI agent to grant excessive allowance to a contract, leading to unintended token transfers or loss of funds.

From the tool's own definition: "approve_jst_for_voting - Approve JST token for the WJST voting contract. This is a token approval operation that modifies allowance state on the TRON blockchain."

## Use case

AI agents use approve_jst_for_voting to create or update resources in Justlend, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Justlend environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Justlend:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "approve_jst_for_voting": {
      "limits": [
        {
          "counter": "approve_jst_for_voting_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Justlend (103)

- `return_energy_rental` — Destructive — https://policylayer.com/tools/justlend-mcp-server-justlend/return-energy-rental.md
- `buy_energy_direct` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/buy-energy-direct.md
- `claim_rewards` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/claim-rewards.md
- `claim_strx_rewards` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/claim-strx-rewards.md
- `deposit_jst_for_votes` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/deposit-jst-for-votes.md
- `moolah_borrow` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/moolah-borrow.md
- `moolah_liquidate` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/moolah-liquidate.md
- `moolah_repay` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/moolah-repay.md
- `moolah_supply_collateral` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/moolah-supply-collateral.md
- `moolah_vault_deposit` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/moolah-vault-deposit.md
- `moolah_vault_withdraw` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/moolah-vault-withdraw.md
- `moolah_withdraw_collateral` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/moolah-withdraw-collateral.md
- `rent_energy` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/rent-energy.md
- `repay` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/repay.md
- `supply` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/supply.md
- `transfer_trc20` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/transfer-trc20.md
- `transfer_trx` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/transfer-trx.md
- `withdraw` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/withdraw.md
- `withdraw_all` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/withdraw-all.md
- `withdraw_votes_from_proposal` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/withdraw-votes-from-proposal.md
- `withdraw_votes_to_jst` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/withdraw-votes-to-jst.md
- `wrap_trx` — Financial — https://policylayer.com/tools/justlend-mcp-server-justlend/wrap-trx.md
- `borrow` — Read — https://policylayer.com/tools/justlend-mcp-server-justlend/borrow.md
- `calculate_energy_rental_price` — Read — https://policylayer.com/tools/justlend-mcp-server-justlend/calculate-energy-rental-price.md
- `check_allowance` — Read — https://policylayer.com/tools/justlend-mcp-server-justlend/check-allowance.md
- `check_jst_allowance_for_voting` — Read — https://policylayer.com/tools/justlend-mcp-server-justlend/check-jst-allowance-for-voting.md
- `check_strx_withdrawal_eligibility` — Read — https://policylayer.com/tools/justlend-mcp-server-justlend/check-strx-withdrawal-eligibility.md
- `claim_moolah_mining_period` — Read — https://policylayer.com/tools/justlend-mcp-server-justlend/claim-moolah-mining-period.md
- `claim_v1_mining_period` — Read — https://policylayer.com/tools/justlend-mcp-server-justlend/claim-v1-mining-period.md
- `estimate_lending_energy` — Read — https://policylayer.com/tools/justlend-mcp-server-justlend/estimate-lending-energy.md
- …and 73 more: https://policylayer.com/tools/justlend-mcp-server-justlend.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=justlend-mcp-server-justlend · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/justlend-mcp-server-justlend