[eric] browser: the read script asks for the whole page, not the model loop's smaller default

backend/apps/agents/browser/browser_read_script.py

@@ -19,7 +19,7 @@ logger = logging.getLogger(__name__)
 ToolRunner = Callable[[str, Dict, str, str], Awaitable[Dict]]
 
 P_MIN_PAGE_CHARS = 500
-P_MAX_PAGE_CHARS = 24000
+MAX_PAGE_CHARS = 24000
 P_TEXT_TIMEOUT_S = 8.0
 P_AUX_TIMEOUT_S = 12.0
 # Prestage's click often lands here while the SPA is still hydrating (measured: a
@@ -107,8 +107,12 @@ async def run_read_script(
             prev = -1
             text, url = "", ""
             for attempt in range(MAX_READS):
+                # Ask for the whole budget we can actually use. The handler's default is sized for the
+                # main loop's context, not for this one aux call, and taking that default meant half
+                # our reads arrived pre-truncated with the answer sitting just past the cut.
                 r = await asyncio.wait_for(
-                    execute_tool("BrowserGetText", {}, browser_id, tab_id), timeout=P_TEXT_TIMEOUT_S)
+                    execute_tool("BrowserGetText", {"max_chars": MAX_PAGE_CHARS}, browser_id, tab_id),
+                    timeout=P_TEXT_TIMEOUT_S)
                 text = str(r.get("text") or "") if isinstance(r, dict) and "error" not in r else ""
                 url = str(r.get("url") or "") if isinstance(r, dict) else ""
                 if len(text) >= P_MIN_PAGE_CHARS and 0 <= prev <= len(text) <= prev * (1 + P_STABLE_GROWTH):
@@ -131,7 +135,7 @@ async def run_read_script(
                 aux_client.messages.create(
                     model=aux_model, max_tokens=500, temperature=0, system=P_SYSTEM,
                     messages=[{"role": "user", "content": (
-                        f"Request: {task[:1200]}\n\nPage text:\n{page[:P_MAX_PAGE_CHARS]}")}],
+                        f"Request: {task[:1200]}\n\nPage text:\n{page[:MAX_PAGE_CHARS]}")}],
                 ), timeout=P_AUX_TIMEOUT_S))
             ms = int((time.monotonic() - t0) * 1000)
             answer = is_answer(reply)

backend/tests/test_browser_read_script.py

@@ -163,3 +163,27 @@ def test_a_page_that_simply_lacks_the_field_is_still_an_answer():
         "Title: 'How to open a jar'. Channel: Kitchen Tips. 1.2M views.",
     ):
         assert rs.is_answer(answer) == answer, answer
+
+
+def test_the_read_asks_for_its_whole_budget_not_the_loops_default():
+    """The handler's default char cap is sized for the MAIN model loop's context, not for this one
+    cheap aux call. Taking that default silently truncated the page: measured, 9 of 18 live reads
+    came back at EXACTLY the cap, and on a reddit thread the comment scores sit past the post body,
+    so the answer was cut off and a 100-220s model loop went looking for what we had removed."""
+    asked = {}
+
+    async def run_tool(name, params, browser_id, tab_id):
+        asked.update(params or {})
+        return {"text": PAGE, "url": "https://www.reddit.com/r/x/comments/1/y"}
+
+    aux = Aux("The top comment is by u/someone with 387 upvotes.")
+    out = asyncio.run(rs.run_read_script(aux, "m", "top comment?", "b1", "t1", run_tool))
+    assert out == "The top comment is by u/someone with 387 upvotes."
+    assert asked.get("max_chars") == rs.MAX_PAGE_CHARS, (
+        f"read must ask for the {rs.MAX_PAGE_CHARS} chars it can use, asked {asked!r}")
+
+
+def test_the_budget_it_asks_for_is_the_budget_it_sends():
+    """If the ask and the send drift apart we are either paying for text we discard, or discarding
+    text we paid for. They are the same number by construction."""
+    assert rs.MAX_PAGE_CHARS >= 24000

frontend/src/shared/browserCommandHandler.ts

@@ -257,9 +257,20 @@ async function evalViaExecuteJs(wv: BrowserWebview, code: string): Promise<any>
   return first.value;
 }
 
-async function handleGetText(wv: BrowserWebview): Promise<Record<string, any>> {
+// What the MAIN model loop gets. Every read lands in its context, so this stays modest on purpose.
+const GET_TEXT_DEFAULT_CHARS = 15000;
+// Ceiling for a caller that asks for more. The read script (one cheap aux call with its own context)
+// asks for its full budget: measured, 9 of 18 of its reads came back at EXACTLY 15000 chars, meaning
+// cut off, and on a reddit thread the comment scores sit after the post body, so they were never in
+// the text it was handed. It then declined, and a 100-220s model loop went scrolling for what we had
+// truncated ourselves.
+const GET_TEXT_MAX_CHARS = 30000;
+
+async function handleGetText(wv: BrowserWebview, params: Record<string, any> = {}): Promise<Record<string, any>> {
+  const asked = Number(params.max_chars) || GET_TEXT_DEFAULT_CHARS;
+  const cap = Math.min(Math.max(asked, 1000), GET_TEXT_MAX_CHARS);
   const text: string = await evalInPage(wv,
-    'document.body.innerText.substring(0, 15000)'
+    `document.body.innerText.substring(0, ${cap})`
   );
   // Sampled HERE (on a read), not on navigate: by the time the agent reads the page, the SPA's XHR/fetch have fired, so routes are actually captured.
   const routes_available = await countSafeRoutes(wv);
@@ -2028,7 +2039,7 @@ async function runBrowserCommand(
         result = await handleScreenshot(wv, params);
         break;
       case 'get_text':
-        result = await handleGetText(wv);
+        result = await handleGetText(wv, params);
         break;
       case 'get_console':
         result = await handleGetConsole(wv);