PDPP

Mcp Adapter

Created Updated openspec/changes/add-aggregate-other-rollup/specs/mcp-adapter/spec.mdView on GitHub →

MODIFIED Requirements

Requirement: MCP Aggregate Tool Surfaces Truncation Signals In-Band

The MCP aggregate tool description SHALL inform models that grouped responses include other_count (the sum of counts for groups/buckets beyond limit) so that truncation can be detected without a second round trip. The tool's text summarizer SHALL include other_count in the model-visible content[] summary when the resource server returns it.

Scenario: Aggregate description mentions other_count

  • WHEN an MCP client lists tools
  • THEN the aggregate tool description SHALL mention other_count and explain that a positive value signals top-N truncation

Scenario: Aggregate text summary includes other_count when present

  • WHEN the resource server returns a grouped aggregate response that includes other_count
  • THEN the aggregate tool's model-visible content[] text summary SHALL include the other_count value
  • AND the value SHALL appear alongside the group preview so models can assess completeness without inspecting structuredContent