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

Beyond the annotations (which only state readOnly=false, idempotent=false, etc.), the description warns about a critical gotcha: header rows are treated as data and will be fed to bots, so they should not be added. It also discloses the confirmation requirement, adding genuine behavioral context that the annotations do not convey.

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?

Three sentences, each earning its place: the first states the core action, the second explains a non-obvious data formatting constraint, and the third provides a user-confirmation rule. The most important operational warning is front-loaded and clearly stated.

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 nested schema and no output schema, the description covers the main non-obvious aspects: header rows, zero-based indexing, and confirmation before creation. It is slightly incomplete in not mentioning what happens on success or what the return value is, but this does not block correct invocation.

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 description adds meaningful detail for the 'values' parameter by explaining zero-based indexing and the no-header-row rule, which goes beyond the schema's minimal 'data rows only' note. However, 'projectId' is not described in the schema or the description, so parameter semantics are only partially enriched.

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: 'Create a new dataset in a project.' It also clarifies the essential domain behavior that every row is treated as data with zero-based column indexing, which helps distinguish this from generic create operations. This is precise and immediately actionable.

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 a clear precondition: confirm with the user before creating a dataset unless explicitly asked. However, it does not mention when to prefer alternatives like append_dataset_rows or update_dataset, so routing between sibling tools is only implied rather than explicit.

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