format_cells

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds valuable behavioral context beyond annotations: formatting only affects appearance, not cell values; flags are tri-state (true/false/unset); open-ended ranges are rejected; dry_run returns resolved target without writing. No contradiction with annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true). Minor gap: no mention of authorization or rate limits, but not critical.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single paragraph but well-structured: first sentence defines purpose, then a1_range guidelines, flag behavior, dry_run, and alternative tools. Every sentence serves a purpose without redundancy. It is concise yet informative.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the parameter count (6), required fields (2), and no output schema, the description covers essential behavior: formatting only, parameter semantics, range constraints, dry_run, and boundaries with other tools. It does not mention error handling or return value shape (no output schema), but these are minor omissions. Overall, it equips an agent to use the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, but the description compensates by explaining the a1_range format, the tri-state nature of bold/italic/underline, and the dry_run parameter. The 'item' parameter is not elaborated beyond being a spreadsheet identifier, but overall the description adds significant meaning beyond the bare schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action (set text formatting), the resource (spreadsheet cells in a bounded A1 range), and the specific properties (bold/italic/underline). It uses a specific verb+resource structure and distinguishes from sibling tools like append_rows or clear_range by focusing on formatting.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit guidance on when to use the tool: for setting text formatting on a spreadsheet range. It explains the a1_range format, the tri-state flag behavior, and the dry_run parameter. It also directs users to alternative tools for heading/bullets/rich text (append_text/create_document with markdown=true), helping agents choose correctly.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.