format_number

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

No annotations are provided, so the description must disclose behavioral traits such as whether the tool modifies existing formatting, requires specific permissions, or has any side effects. The description only says 'Apply number formatting' which implies a mutation but provides no further details.

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?

Single sentence, front-loaded, no redundant words. Efficient.

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 modification tool with 4 required parameters and no annotations, the description is very brief. It does not explain the effect on existing formatting, return value, or potential errors. However, the presence of an output schema may reduce the need for return value details. Still, more context would improve completeness.

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?

Input schema has 100% coverage, so the description adds no additional meaning beyond the schema. The schema already describes each parameter, including examples for format_string. The description does not enhance parameter semantics.

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?

Clearly states the action (Apply) and resource (number formatting to a range of cells), distinguishing it from sibling formatting tools like format_alignment or format_font.

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 versus alternative formatting tools or when to choose a different approach. The sibling tools include other formatting options, but the description does not clarify when to use number formatting specifically.

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