diff --git a/cmd/nomos/agent.go b/cmd/nomos/agent.go
index 0d69785..aeb4d7f 100644
--- a/cmd/nomos/agent.go
+++ b/cmd/nomos/agent.go
@@ -721,7 +721,23 @@ func (a *agent) buildTools(sessionID string) ([]openai.ChatCompletionToolParam,
 	return tools, nil
 }
 
+// listToolsFull returns the MCP server's tool list, cached on this client
+// after the first call (see mcpClient.toolsCache). Fix F1 of
+// plans/2026-07-11-nomos-agent-code-review.md: buildTools calls this at the
+// start of every chat turn, including every auto-continuation resume — the
+// tool list is static for the lifetime of one MCP connection, so re-fetching
+// it every single time was avoidable network+parsing work on the hot path.
+// Cache invalidates on reconnectLocked (an api restart may change what's
+// registered).
 func (c *mcpClient) listToolsFull() ([]toolDef, error) {
+	c.toolsMu.Lock()
+	if c.toolsCache != nil {
+		cached := c.toolsCache
+		c.toolsMu.Unlock()
+		return cached, nil
+	}
+	c.toolsMu.Unlock()
+
 	resp, err := c.doRequest("tools/list", map[string]any{})
 	if err != nil {
 		return nil, err
@@ -744,5 +760,9 @@ func (c *mcpClient) listToolsFull() ([]toolDef, error) {
 			InputSchema: t.InputSchema,
 		}
 	}
+
+	c.toolsMu.Lock()
+	c.toolsCache = out
+	c.toolsMu.Unlock()
 	return out, nil
 }
diff --git a/cmd/nomos/main.go b/cmd/nomos/main.go
index 0982544..63e0b48 100644
--- a/cmd/nomos/main.go
+++ b/cmd/nomos/main.go
@@ -481,6 +481,18 @@ type mcpClient struct {
 	http      *http.Client
 	nextID    int
 	mu        sync.Mutex // this client is one stateful MCP session; serialize ITS OWN calls
+
+	// toolsCache holds the last tools/list result. The tool list is static
+	// for the lifetime of one MCP connection — it only changes when the api
+	// process (re)registers tools, i.e. on a restart, which this client
+	// already detects and reacts to via reconnectLocked. Without this,
+	// buildTools (called at the start of EVERY chat turn, including every
+	// auto-continuation resume) paid a full tools/list round-trip every
+	// single time for a list that's almost always identical to the last one.
+	// Guarded separately from mu (not reused) so a cache check never
+	// contends with an in-flight doRequest call for a different method.
+	toolsMu    sync.Mutex
+	toolsCache []toolDef
 }
 
 func newMCPClient(baseURL string) (*mcpClient, error) {
@@ -540,6 +552,12 @@ func (c *mcpClient) doRequest(method string, params map[string]any) (*mcpJSONRPC
 // reconnectLocked re-initializes the MCP session. The caller must hold c.mu.
 func (c *mcpClient) reconnectLocked() error {
 	c.sessionID = ""
+	// A reconnect means the api process was restarted (or forgot us) — its
+	// tool registration may have changed, so the cached list is no longer
+	// trustworthy.
+	c.toolsMu.Lock()
+	c.toolsCache = nil
+	c.toolsMu.Unlock()
 	resp, err := c.send("initialize", map[string]any{
 		"protocolVersion": "2024-11-05",
 		"capabilities":    map[string]any{},