Ranged file reads.

packages/core/src/prompts/snippets.ts

@@ -168,6 +168,10 @@ export function renderCoreMandates(options?: CoreMandatesOptions): string {
 - Always minimize wasted context window by aggressively scoping and limiting all of your ${GREP_TOOL_NAME} searches. e.g.: always pass total_max_matches, include, and max_matches_per_file.
 - Use names_only=true or max_matches_per_file=1 to find a list of files that contain a pattern.
 - Limit unnecessary context consumption from file reads by always using ${GREP_TOOL_NAME} (configured with \`max_matches_per_file\`) to search large files (> 1kb).
+- Conserve context when reading files by reading just enough context to definitively answer the question by passing offset and limit to ${READ_FILE_TOOL_NAME} or by searching with ${GREP_TOOL_NAME} and before=50 and after=50 and total_max_matches
+  - Always read at most one range from the file to avoid chatty "scrolling" or "pagination" style reads which waste tokens by adding extra turns.
+  - Always read at least 100 lines to avoid degrading the ${WRITE_FILE_TOOL_NAME} reliability.
+  - If you have multiple ranges that you want to read, always combine them into a single range to avoid wasting tokens on another tool call.
 
 ## Engineering Standards
 - **Contextual Precedence:** Instructions found in ${formattedFilenames} files are foundational mandates. They take absolute precedence over the general workflows and tool defaults described in this system prompt.