Google Docs authoring

Locate text, never compute indexes (the #1 source of bugs)

Docs edits address zero-based UTF-16 index ranges within one tab, and every write SHIFTS later indexes. Guessed or stale indexes silently hit the wrong paragraphs - the classic symptom is two lists merging into one continued numbering. The tools remove the need for index math:

• find_text returns FRESH {start, end} ranges for exact text - the direct source of indexes for apply_text_style, apply_paragraph_style, delete_content, and set_paragraph_format. Locate, then edit, in back-to-back calls.
• create_list takes firstItemText/lastItemText anchors and resolves the range itself: name the first and last item paragraphs and no index ever touches your hands. Use one create_list per list with the right preset (BULLET_* for bullets, NUMBERED_* for numbers); never stretch one call across two visually separate lists.

When a range must come from structure instead of a phrase (styling a whole paragraph, addressing a table), read it from read_document elements: a paragraph's {start, end} is the range for paragraph-level tools. END IS EXCLUSIVE: one short misses the last character, one long styles the character after the phrase (the classic italic-or-link off-by-one).

When raw indexes are unavoidable: read_document first, compute ONE edit, pass requiredRevisionId, apply, and re-read before the next positional edit. Order multi-part positional work BACK-TO-FRONT (highest index first) when re-reading between steps is too expensive; earlier ranges stay valid.

Creating a document

create_document makes a BLANK doc (its API ignores content), so plan:

• Content known up front: prefer google-drive google_drive_create_file with Markdown (target_mime_type: ...document), which imports headings, lists, and tables in one call and can target a folder.
• Building incrementally: create_document, then insert_text with index omitted to APPEND each paragraph; append mode reads the tail itself and is revision-guarded automatically. paragraphStyle styles the new paragraphs and bold/italic style the inserted text in the same call, so a well-structured document is a sequence of appends with no styling pass.
• Doc creates cannot set a parent folder. When placement matters, create and then google-drive google_drive_move_or_rename with destination_folder_id.

Structure is not optional

A document without hierarchy reads as a text dump. Default shape for any report/memo/notes request: a TITLE paragraph, an italic byline or date line, HEADING_2 per section, short body paragraphs with bold on the phrases that matter, and bulleted lists for enumerations. Use insert_text's paragraphStyle/bold/italic arguments as you write rather than styling afterwards.

Styling

• Character styling (apply_text_style): bold/italic/underline/strike, fontSize, fontFamily, textColor/backgroundColor as #RRGGBB, linkUrl. Exclusive END index: to style one paragraph without its trailing newline, use end - 1 from the read.
• Paragraph styling: apply_paragraph_style for named styles (TITLE/HEADING_1..6), set_paragraph_format for alignment, indents, and line spacing (percent, 100 = single).
• Lists: create_list over the paragraphs' range; each newline-separated paragraph becomes one item. Insert the plain lines first, then bullet them.
• The preset is part of correctness: enumerations get a BULLET_* preset by default; NUMBERED_* only when the content is ordered (steps, rankings) or the request says numbered.
• Before bulleting, check the read for paragraphs that ALREADY show a leading bullet - text appended directly after a list inherits its membership, and create_list over such paragraphs restyles the ORIGINAL list, continuing its numbering (a second list showing 4, 5, 6). Strip first: create_list with remove: true over exactly the new paragraphs, then apply the wanted preset.

Tables and images

• insert_table inserts an EMPTY grid. To fill it: re-read (cells appear with their own index ranges) and insert_text into cells from the LAST cell to the first, so earlier cell indexes stay valid.
• Style a table AFTER filling it, addressing it by the table element's start from read_document: set_table_cell_shading the header row (pick the row's text color against that fill), merge_table_cells for a title cell spanning columns (top-left content survives, the rest is dropped), set_table_column_width for fixed widths in points. Structural edits (merge) shift indexes: re-read before further text edits.
• insert_image needs a PUBLICLY fetchable URL (Google fetches it; auth walls and private hosts fail), PNG/JPEG/GIF. Size with width/height in points (aspect kept when only one is set).
• insert_page_break starts a new page at an index.

Headers and footers

set_header_footer sets the default header or footer in one call: it creates the segment when the doc has none, replaces the text otherwise, and empty text clears it. The text is static (no page-number fields exist in the API); it applies to the first tab. Never insert_text a fake header into the body - it scrolls away with the content.

Bulk text ops

replace_text replaces literal strings everywhere (or in named tabs) with no index math; prefer it for renames and corrections. delete_content rejects ranges that split table structure or surrogate pairs; deleting a paragraph's final newline merges it with the next.

Verify your work

Re-read with read_document for structure and styles, or google-drive google_drive_read_file for the whole doc as Markdown, or google_drive_export_file (pdf) when the visual result matters. After any styling call, confirm the styled span covers exactly the intended text before moving on.