Executes write SQL statements—INSERT, UPDATE, DELETE, CREATE, ALTER, DROP—to modify database schema or data. Disabled when the server is in read-only mode.
Execute a write SQL statement: INSERT, UPDATE, DELETE, CREATE, ALTER, DROP. Disabled in read-only mode.
| Name | Required | Description | Default |
|---|---|---|---|
| sql | Yes | SQL statement to execute |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the behavioral disclosure burden. It does disclose that the tool performs writes and is disabled in read-only mode, and it lists potentially destructive statements like DROP. However, it does not warn about irreversibility, side effects, or what happens on execution.
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?
One compact sentence conveys the tool's purpose, the allowed statement types, and an important runtime constraint. No filler or redundant phrasing.
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 simple one-parameter tool with no output schema, the description is largely complete: it tells the agent what kind of SQL is allowed and when the tool is unavailable. It could mention return behavior (e.g., affected rows or errors), but the core invocation context is fully covered.
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 100%, so the schema already documents the 'sql' parameter. The description adds useful context by limiting execution to write statements, but it does not provide parameter-specific details beyond what the schema conveys.
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 ('Execute') and a clear resource ('a write SQL statement'), enumerating exact statement types (INSERT, UPDATE, DELETE, CREATE, ALTER, DROP). This clearly differentiates it from sibling tools like db_query, which handles reads.
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 description makes clear this tool is for write statements only, which implies it should not be used for SELECT queries (where db_query would be appropriate). It also notes it is disabled in read-only mode, giving useful context, but it does not explicitly name the alternative read tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.