standard

ToolAnnotations

Interface in the MCP schema holding four boolean hints about a tool's behaviour, each with a documented default and a NOTE warning clients not to rely on them from untrusted servers.

Known aliases

destructiveHint
idempotentHint
openWorldHint
readOnlyHint

Relationships

No evidence-backed relationships are recorded.

Current clusters

build1 publisher

Leaving readOnlyHint unset is what makes a missing destructiveHint default to true

The MCP schema defaults destructiveHint to true, but only where readOnlyHint is false. A ChatGPT app directory scanner asked for the field anyway on four read-only tools, and the tools came out of it behaving exactly as before.

Publishers:dev.to

Reality

Evidence74
Adoption22
Hype gap−8
Incentives40
Confidence66