gws.sheets.add_tab

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

Annotations already indicate mutation and non-idempotency, but the description adds valuable context: the operation is atomic ('Returns an error — without changing anything — if a tab with the same title already exists'), reports the default index behavior, and lists return fields. This goes well beyond the structured annotations.

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 compact and front-loaded with the core action. Each sentence adds relevant information: the operation, the position semantics, the failure mode, return data, and the mutation warning. No redundant filler.

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 tool's mutation risk poorly covered by annotations, the description fully addresses what an agent needs: what action is performed, how position is interpreted, what happens on duplicate titles, what is returned, and when to seek user confirmation. There is no output schema, so the return-value mention is especially important and sufficient.

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 coverage is 100%, so the schema documents all parameters. The description adds meaning for the 'index' parameter (zero-based, defaults to last), describes the duplicate-title constraint in operational terms, and clarifies return values — a meaningful supplement to the 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 states a specific verb and resource: 'Add a new, empty tab (sheet) to a Google Spreadsheet'. It further distinguishes itself from siblings by emphasizing the empty-tab creation and the AddSheetRequest mechanism, making it unambiguous versus duplicate_tab or create.

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 gives an explicit usage guideline: confirm intent with the user before modifying documents not created in the session. It also clarifies the duplicate-title error behavior. It does not explicitly name sibling alternatives or when-not-to-use conditions, but the guidance is clear enough for safe usage.

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