diff --git a/lib/roast/cogs/agent/providers/pi/messages/tool_call_message.rb b/lib/roast/cogs/agent/providers/pi/messages/tool_call_message.rb
index effacf9c..3491c081 100644
--- a/lib/roast/cogs/agent/providers/pi/messages/tool_call_message.rb
+++ b/lib/roast/cogs/agent/providers/pi/messages/tool_call_message.rb
@@ -32,24 +32,80 @@ def initialize(id:, name:, arguments:)
               def format
                 return unless name
 
-                case name.to_s.downcase
-                when "bash"
-                  "BASH #{arguments[:command]}"
-                when "read"
-                  "READ #{arguments[:path]}"
-                when "edit"
-                  "EDIT #{arguments[:path]}"
-                when "write"
-                  "WRITE #{arguments[:path]}"
-                when "grep"
-                  "GREP #{arguments[:pattern]} #{arguments[:path]}"
-                when "find"
-                  "FIND #{arguments[:pattern]} #{arguments[:path]}"
-                when "ls"
-                  "LS #{arguments[:path]}"
-                else
-                  "TOOL [#{name}] #{arguments.inspect}"
-                end
+                format_method_name = "format_#{name.to_s.downcase}".to_sym
+                return send(format_method_name) if respond_to?(format_method_name, true)
+
+                format_unknown
+              end
+
+              TRUNCATE_LIMIT = 45
+
+              private
+
+              #: () -> String
+              def format_bash
+                command = truncate(arguments[:command])
+                command.empty? ? "BASH" : "BASH #{command}"
+              end
+
+              #: () -> String
+              def format_read
+                path = arguments[:path]
+                path.to_s.empty? ? "READ" : "READ #{path}"
+              end
+
+              #: () -> String
+              def format_write
+                path, content = arguments.values_at(:path, :content)
+                lines = content.to_s.lines
+                preview = truncate(lines.first.to_s.strip)
+                count = lines.length
+                line_label = count == 1 ? "line" : "lines"
+                "WRITE #{path} \"#{preview}\" (+#{count} #{line_label})"
+              end
+
+              #: () -> String
+              def format_edit
+                path = arguments[:path]
+                edits = arguments[:edits] || []
+                count = edits.length
+                edit_label = count == 1 ? "edit" : "edits"
+                "EDIT #{path} (#{count} #{edit_label})"
+              end
+
+              #: () -> String
+              def format_grep
+                pattern, path, glob = arguments.values_at(:pattern, :path, :glob)
+                base = "GREP \"#{truncate(pattern)}\""
+                base = "#{base} #{path}" if path.present?
+                glob.present? ? "#{base} (glob=#{glob})" : base
+              end
+
+              #: () -> String
+              def format_find
+                pattern, path = arguments.values_at(:pattern, :path)
+                path.present? ? "FIND #{pattern} (in #{path})" : "FIND #{pattern}"
+              end
+
+              #: () -> String
+              def format_ls
+                path = arguments[:path]
+                path.to_s.empty? ? "LS" : "LS #{path}"
+              end
+
+              #: () -> String
+              def format_unknown
+                label = name.to_s.upcase
+                return label if arguments.empty?
+
+                details = arguments.map { |key, value| "#{key}: #{truncate(value.inspect)}" }.join(", ")
+                "#{label} #{details}"
+              end
+
+              #: (String?) -> String
+              def truncate(str)
+                s = str.to_s
+                s.length > TRUNCATE_LIMIT ? "#{s[0...TRUNCATE_LIMIT - 3]}..." : s
               end
             end
           end
diff --git a/lib/roast/cogs/agent/providers/pi/messages/tool_result_message.rb b/lib/roast/cogs/agent/providers/pi/messages/tool_result_message.rb
index ff2f59f1..0f74095d 100644
--- a/lib/roast/cogs/agent/providers/pi/messages/tool_result_message.rb
+++ b/lib/roast/cogs/agent/providers/pi/messages/tool_result_message.rb
@@ -30,23 +30,94 @@ def initialize(tool_call_id:, tool_name:, content:, is_error:)
                 @tool_name = tool_name
                 @content = content
                 @is_error = is_error
+                @name = (tool_name || "unknown").to_s #: String
+                @input = {} #: Hash[Symbol, untyped]
               end
 
               #: (PiInvocation::Context) -> String?
               def format(context)
-                tool_call = context.tool_call(tool_call_id)
-                name = tool_name || tool_call&.name || "unknown"
-                status = is_error ? "ERROR" : "OK"
-
-                # Truncate long tool results for progress display
-                c = content
-                display_content = if c && c.length > 200
-                  "#{c[0..197]}..."
-                else
-                  c
-                end
-
-                "#{name.upcase} #{status}#{display_content ? " #{display_content}" : ""}"
+                call = context.tool_call(tool_call_id)
+                @name = (tool_name || call&.name || "unknown").to_s
+                @input = call&.arguments || {}
+
+                return error_line if is_error
+
+                format_method_name = "format_#{@name.downcase}".to_sym
+                return send(format_method_name) if respond_to?(format_method_name, true)
+
+                format_unknown
+              end
+
+              TRUNCATE_LIMIT = 45
+
+              private
+
+              #: () -> String
+              def format_bash
+                lines = content.to_s.lines
+                count = lines.length
+                ok_line("#{count} #{"line".pluralize(count)}")
+              end
+
+              #: () -> String
+              def format_read
+                count = content.to_s.lines.length
+                ok_line("#{count} #{"line".pluralize(count)}")
+              end
+
+              #: () -> String
+              def format_write
+                ok_line(@input[:path])
+              end
+
+              #: () -> String
+              def format_edit
+                ok_line(@input[:path])
+              end
+
+              #: () -> String
+              def format_grep
+                lines = content.to_s.lines.map(&:strip).reject(&:empty?)
+                matches, notes = lines.partition { |line| line.match?(%r{\A\S+/}) || line.match?(/\A(?:\S+:)?\d+:/) }
+                count = matches.length
+                note = "NOTE #{truncate(notes.join(" "))}" if matches.any? && notes.any?
+                ok_line("#{count} #{"match".pluralize(count)}", note)
+              end
+
+              #: () -> String
+              def format_find
+                count = content.to_s.lines.map(&:strip).reject(&:empty?).length
+                ok_line("#{count} #{"path".pluralize(count)}")
+              end
+
+              #: () -> String
+              def format_ls
+                count = content.to_s.lines.map(&:strip).reject(&:empty?).length
+                ok_line("#{count} #{"entry".pluralize(count)}")
+              end
+
+              #: () -> String
+              def format_unknown
+                preview = truncate(content.to_s.lines.first.to_s.strip)
+                ok_line(preview)
+              end
+
+              #: (*String?) -> String
+              def ok_line(*parts)
+                summary = parts.select(&:present?).join(" · ")
+                prefix = "#{@name.upcase} OK"
+                summary.present? ? "#{prefix} #{summary}" : prefix
+              end
+
+              #: () -> String
+              def error_line
+                "#{@name.upcase} ERROR #{content.to_s.strip}".strip
+              end
+
+              #: (String?) -> String
+              def truncate(str)
+                s = str.to_s
+                s.length > TRUNCATE_LIMIT ? "#{s[0...TRUNCATE_LIMIT - 3]}..." : s
               end
             end
           end