feat(mcp): support server side instructions (#2015)

Carlos Alexandro Becker created 2 weeks ago

* feat(mcp): support server side instructions

Signed-off-by: Carlos Alexandro Becker <[e-mail]>

* fix: empty lines

Signed-off-by: Carlos Alexandro Becker <[e-mail]>

---------

Signed-off-by: Carlos Alexandro Becker <[e-mail]>

Change summary

internal/agent/agent.go | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

Detailed changes

internal/agent/agent.go

@@ -32,6 +32,7 @@ import (
 	"github.com/charmbracelet/catwalk/pkg/catwalk"
 	"github.com/charmbracelet/crush/internal/agent/hyper"
 	"github.com/charmbracelet/crush/internal/agent/tools"
+	"github.com/charmbracelet/crush/internal/agent/tools/mcp"
 	"github.com/charmbracelet/crush/internal/config"
 	"github.com/charmbracelet/crush/internal/csync"
 	"github.com/charmbracelet/crush/internal/message"
@@ -167,6 +168,21 @@ func (a *sessionAgent) Run(ctx context.Context, call SessionAgentCall) (*fantasy
 	largeModel := a.largeModel.Get()
 	systemPrompt := a.systemPrompt.Get()
 	promptPrefix := a.systemPromptPrefix.Get()
+	var instructions strings.Builder
+
+	for _, server := range mcp.GetStates() {
+		if server.State != mcp.StateConnected {
+			continue
+		}
+		if s := server.Client.InitializeResult().Instructions; s != "" {
+			instructions.WriteString(s)
+			instructions.WriteString("\n\n")
+		}
+	}
+
+	if s := instructions.String(); s != "" {
+		systemPrompt += "\n\n<mcp-instructions>\n" + s + "\n</mcp-instructions>"
+	}
 
 	if len(agentTools) > 0 {
 		// Add Anthropic caching to the last tool.