destructiveHint
destructiveHint is an MCP tool annotation that, when true, warns that the tool may delete or overwrite data rather than only add to it. 85% of tools in our MCP dataset (the 425 open servers we track across every store, not only the 105 behind ChatGPT and Claude listings, with 7,777 tools) set destructiveHint on October 13, 2026, but only 9% set it to true.
- Tools that set it
- 85%
- Set to true
- 9%
- Servers using it
- 343 of 425MCP dataset, every store we track
- Default
- true
More from our data
Most tools that set it use it to say they don't delete or overwrite anything.
It only matters when readOnlyHint is false. The spec's default is true, so a tool that writes and leaves it out should be read as possibly destructive.