Improve read_file summary to mention offset being read.

Author: ericdallo

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Fix custom tools to support argument numbers.
+- Improve read_file summary to mention offset being read.
 
 ## 0.84.2
 

resources/prompts/additional_system_info.md

@@ -1,6 +1,6 @@
 ## Project Environment Context
 
-Workspaces: {workspaceRoots}
+Workspaces: {{workspaceRoots}}
 
 **Path Resolution & Context:**
 *Workspaces:* Directories containing code or data relevant to this session.

src/eca/features/prompt.clj

@@ -35,7 +35,7 @@
 (defn ^:private replace-vars [s vars]
   (reduce
    (fn [p [k v]]
-     (string/replace p (str "{" (name k) "}") (str v)))
+     (string/replace p (str "{{" (name k) "}}") (str v)))
    s
    vars))
 

src/eca/features/tools.clj

@@ -3,6 +3,7 @@
    eca native tools and MCP servers."
   (:require
    [clojure.string :as string]
+   [clojure.walk :as walk]
    [eca.features.tools.chat :as f.tools.chat]
    [eca.features.tools.custom :as f.tools.custom]
    [eca.features.tools.editor :as f.tools.editor]
@@ -38,14 +39,29 @@
     (fn [tool]
       (assoc-some tool :disabled (contains? disabled-tools (:name tool))))))
 
+(defn ^:private replace-string-values-with-vars
+  "walk through config parsing dynamic string contents if value is a string."
+  [m vars]
+  (walk/postwalk
+   (fn [x]
+     (if (string? x)
+       (reduce
+        (fn [s [k v]]
+          (string/replace s (str "{{" (name k) "}}") (str v)))
+        x
+        vars)
+       x))
+   m))
+
 (defn ^:private native-definitions [db config]
   (into
    {}
    (map (fn [[name tool]]
           [name (-> tool
                     (assoc :name name)
-                    (update :description #(-> %
-                                              (string/replace #"\{workspaceRoots\}" (constantly (tools.util/workspace-roots-strs db))))))]))
+                    (replace-string-values-with-vars
+                      {:workspaceRoots (tools.util/workspace-roots-strs db)
+                       :readFileMaxLines (get-in config [:toolCall :readFile :maxLines])}))]))
    (merge {}
           f.tools.filesystem/definitions
           f.tools.shell/definitions

src/eca/features/tools/filesystem.clj

@@ -70,7 +70,7 @@
                                                        ["path" (complement fs/directory?) "$path is a directory, not a file"]]))
       (let [line-offset (or (get arguments "line_offset") 0)
             limit (->> [(get arguments "limit")
-                        (get-in config [:toolCall :readFile :maxLines] 2000)]
+                        (get-in config [:toolCall :readFile :maxLines])]
                        (filter number?)
                        (apply min))
             full-content-lines (string/split-lines (slurp (fs/file (fs/canonicalize (get arguments "path")))))
@@ -89,9 +89,19 @@
                                                " parameter to read more content.")
                                           content)))))
 
-(defn ^:private read-file-summary [{:keys [args]}]
+(defn ^:private read-file-summary [{:keys [args config]}]
   (if-let [path (get args "path")]
-    (str "Reading file " (fs/file-name (fs/file path)))
+    (let [line-offset (get args "line_offset" 0)
+          limit (get args "limit" (get-in config [:toolCall :readFile :maxLines]))
+          sub-read (or line-offset limit)]
+      (format "Reading file %s %s"
+              (fs/file-name (fs/file path))
+              (str
+                (when sub-read
+                  (format "(%s-%s)"
+                          line-offset
+                          limit))
+                )))
     "Reading file"))
 
 (defn ^:private write-file [arguments _]
@@ -321,7 +331,7 @@
                               "line_offset" {:type "integer"
                                              :description "Line to start reading from (default: 0)"}
                               "limit" {:type "integer"
-                                       :description "Maximum lines to read (default: configured in tools.readFile.maxLines, defaults to 2000)"}}
+                                       :description "Maximum lines to read (default: {{readFileMaxLines}})"}}
                  :required ["path"]}
     :handler #'read-file
     :require-approval-fn (tools.util/require-approval-when-outside-workspace ["path"])

test/eca/features/tools_test.clj

@@ -61,7 +61,7 @@
                      :description (format "Only in %s" (h/file-path "/path/to/project/foo"))
                      :parameters some?
                      :origin :native}])
-         (with-redefs [f.tools.filesystem/definitions {"directory_tree" {:description "Only in {workspaceRoots}"
+         (with-redefs [f.tools.filesystem/definitions {"directory_tree" {:description "Only in {{workspaceRoots}}"
                                                                          :parameters {}}}]
            (f.tools/all-tools "123" "agent" {:workspace-folders [{:name "foo" :uri (h/file-uri "file:///path/to/project/foo")}]}
                               {}))))))