auto_fill

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

With no annotations, the description must fully disclose behavior. It mentions 'detecting existing source data' but does not explain how detection works, what patterns are recognized, or whether the operation modifies cells (destructive). Lacks clarity on 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 single sentence, very concise, and front-loaded. However, it sacrifices necessary detail. It is not overly verbose, but the conciseness comes at the cost of completeness.

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 no annotations, no output schema, and 3 parameters with zero schema description coverage, the description is insufficient. It does not provide enough context for an AI to use the tool correctly or anticipate results.

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%, so the description should explain parameter meaning. It only hints at 'range' via 'within an A1 range' but fails to describe 'spreadsheet_id' or 'use_alternate_series'. The AI cannot infer how to use parameters effectively.

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 tool performs an autofill operation within an A1 range by detecting source data. It uses a specific verb ('auto_fill') and resource ('range'), distinguishing it from siblings like copy_range or write_range.

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?

No guidance on when to use this tool vs alternatives (e.g., copy_range, fill series, or manual write). Does not mention prerequisites or scenarios where it is inappropriate.

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