MCP Supabase Server

supabase_execute_sql

Execute raw SQL queries via an RPC endpoint to run custom database operations. Requires the execute_sql function to be created in Supabase.

Instructions

Execute raw SQL query via RPC endpoint (requires execute_sql function to be created in Supabase).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "sql": "<sql>"
    },
    "name": "supabase_execute_sql"
  }
}

Input Schema

Name	Required	Description	Default
`sql`	Yes	Raw SQL query to execute (requires execute_sql RPC function)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 13, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full behavioral burden. It does disclose a meaningful prerequisite (the execute_sql function must be created), but says nothing about permissions, whether arbitrary SQL can mutate or destroy data, transaction behavior, or rate limits — critical omissions for a raw-SQL execution tool.

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?

A single front-loaded sentence with no padding; the parenthetical prerequisite is worth its space. It could be split so the prerequisite reads as a distinct condition, but nothing is wasted.

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

Completeness2/5

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

For a tool that executes arbitrary SQL, with no annotations and no output schema, the description omits destructive-capability warnings, permission requirements, and return expectations. The one prerequisite given is useful but not sufficient for correct invocation.

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?

Schema description coverage is 100% for the single 'sql' parameter, so the schema already documents it and the baseline is 3. The description's parenthetical about the execute_sql RPC function marginally reinforces the schema note but adds no syntax or format detail.

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

Purpose4/5

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

States a specific verb (Execute) and resource (raw SQL query) plus the transport (RPC endpoint), which is more informative than the sibling names supabase_query or supabase_rpc alone. It does not, however, explain how it differs from supabase_rpc or supabase_query, so the agent still has to guess which sibling to pick.

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

Usage Guidelines2/5

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

The description supplies a prerequisite (an execute_sql RPC function must exist in Supabase) but no when-to-use, when-not-to-use, or alternative-selection guidance. With eleven siblings including supabase_query and supabase_rpc, the absence of routing guidance is a real gap.

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

Deploy Server