Format cells

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so safety profile is covered. The description adds genuine non-obvious behavior: partial-update semantics (only supplied options are modified), which the annotations do not convey. It does not mention auth requirements or atomicity of the operation.

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?

Two tightly packed sentences, front-loaded with the action and scope, then the partial-update rule, then the sibling routing. No wasted words.

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 17-parameter mutation tool with no output schema and low schema coverage, the description covers the option surface and the crucial partial-update behavior plus alternative routing. It stops short of explaining how clear_formatting interacts with other supplied options or what the result looks like.

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?

With 17 parameters and only 35% schema description coverage, the description should carry more weight. It lists formatting categories (font, colors, number formats, alignment, wrapping, borders) which aids discovery, but adds no syntax or semantics beyond what the schema already shows for enums, nested objects, or booleans.

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?

Names a specific verb (Apply formatting) and resource (a range) and enumerates the formatting categories covered, so the agent knows exactly what it does. It also explicitly distinguishes itself from the sibling format_ranges, making disambiguation possible without opening either schema.

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?

"Only provided options are changed" clarifies the update model and "To style several ranges differently in one go, use format_ranges" gives an explicit alternative with its selecting condition. It lacks guidance on prerequisites (account/permissions) or when to prefer clear_range over clear_formatting, but the core routing is present.

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