[DOCS] Read tool docs still describe oversized whole-file reads as hard errors

Documentation Type

Incorrect/outdated documentation

Documentation Location

https://code.claude.com/docs/en/tools-reference

Section/Topic

Read tool behavior

Current Documentation

The docs currently say:

## Read tool behavior The Read tool takes a file path and returns the contents with line numbers. Claude is instructed to always pass absolute paths. By default, Read returns the file from the start. Files over a size threshold return an error rather than partial content, prompting Claude to retry with offset and limit to read a specific range.

What's Wrong or Missing?

This section still documents the old failure mode for oversized whole-file reads.

For the Claude Code v2.1.145 release, the Read tool behavior was changed so a whole-file read that exceeds the token limit returns a truncated first page with a PARTIAL view notice instead of hard-failing immediately. The current docs still say the tool returns an error rather than partial content, so they describe the wrong user-visible behavior and omit the PARTIAL view fallback entirely.

Suggested Improvement

Update the Read tool behavior section to describe the current fallback behavior.

Before:

Files over a size threshold return an error rather than partial content, prompting Claude to retry with offset and limit to read a specific range.

After:

When a whole-file read would exceed the token limit, Read returns a truncated first page labeled as PARTIAL view instead of failing immediately. Claude can then continue with offset and limit to read additional ranges, or raise CLAUDE_CODE_FILE_READ_MAX_OUTPUT_TOKENS when a larger full-file read is appropriate.

Impact

Medium - Makes feature difficult to understand

Additional Context

Affected Pages:

| Page | Line(s) | Context |
|------|---------|---------|
| https://code.claude.com/docs/en/tools-reference | 246-250 | Read tool behavior says oversized reads return an error rather than partial content |

Related Pages:

| Page | Context |
|------|---------|
| https://code.claude.com/docs/en/env-vars | Documents CLAUDE_CODE_FILE_READ_MAX_OUTPUT_TOKENS, which is related to oversized file reads |

Total scope: 1 primary page affected

Version context: Behavior change called out in Claude Code v2.1.145