fill_excel_template

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

With no annotations, the description carries full burden. It discloses that recalculate defaults to true and returns a base64 XLSX, but does not mention whether the original template is modified (it is not—returns new file), authorization needs, or error conditions. The information is present but could be more explicit about non-destructive nature and side effects.

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 clean docstring format (Args, Returns) with no wasted words. Each sentence earns its place: the opening sentence covers the core action, parameter list includes details, and return type is specified. It is front-loaded and easy to parse.

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?

Despite moderate complexity (template filling with cells and tables) and no annotations, the description covers parameters, defaults, and return value. It could mention input validation or template format requirements, but overall it is sufficient for an agent to use the tool correctly. The presence of an output schema is not utilized but the description compensates well.

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%, yet the description explains all four parameters with concrete examples: 'template_base64: Base64-encoded Excel template file', 'values: Cell values... key = cell ref like Sheet1!A1 or named range', 'tables: Table data... key = range name, value = row arrays', and the default for recalculate. This adds substantial meaning beyond the schema types.

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 ('Fill') and resource ('Excel template'), specifying 'with data at named cells and ranges'. This is unambiguous and distinguishes from siblings like 'generate_excel' which creates new files, or 'csv_to_excel' which converts CSV. The verb+resource combination is specific.

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 does not provide any guidance on when to use this tool versus alternatives. No context is given about prerequisites or typical use cases. For example, it could mention that this is for populating existing templates rather than generating from scratch. The absence of usage recommendations limits the agent's decision-making.

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