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

With no annotations, the description carries the burden. It adds the useful constraint 'currently only title' and implies it only updates that property. However, it does not disclose side effects, permissions, or reversibility, leaving some behavioral ambiguity for an update operation.

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?

A single, well-structured sentence with no redundancy. It front-loads the action and resource, and the parenthetical limitation is concise and useful.

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?

For a simple update tool with only two parameters and no output schema, the description is nearly sufficient. It states the scope and limitation, but the lack of any behavioral notes (e.g., whether the operation overwrites the existing title) is a minor gap given the absence of annotations.

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?

The schema covers 100% of the parameters with descriptions, so baseline is 3. The description adds meaning by clarifying that 'title' is the only supported workbook-level property and that the operation targets the workbook, which goes slightly beyond the schema's basic 'New title' and 'Sheet (workbook) ID'.

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 identifies the action ('Update'), the resource ('spreadsheet/sheet/workbook'), and the scope ('workbook-level properties'). It explicitly limits to 'currently only title', which distinguishes it from sibling tools like update_document and update_sheet_tab.

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 clear context by specifying 'workbook-level properties', indicating this is for the workbook (not a tab or document). It does not explicitly name alternatives or exclusions, but the 'currently only title' limitation and the sibling names help the agent infer when to use this tool.

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