set_cells

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

With no annotations, the description carries the full burden and discloses substantial behavior: numeric values are written numerically and other values as text, formulas starting with '=' are evaluated by Calc, and sheet defaults to the first sheet. The main gap is that the promised return '{written}' is not explained (count vs. list), and overwrite behavior of existing cells is never mentioned.

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 compact and front-loaded, opening with the core action and return before moving to the parameter format. Each sentence adds distinct information — example structure, coercion rules, formula evaluation, sheet selection — with no filler or repetition of what the schema already shows.

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 three-parameter mutation tool with no annotations and no output schema, the description covers invocation well: both required parameters are usable from the text and the optional sheet parameter is fully explained. It falls short only in not clarifying what the '{written}' return value contains and in not routing the agent away from formatting siblings.

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 must compensate, and it does: the cells parameter is fully explained with a concrete example and distinct rules for value vs. formula entries, and sheet is specified as name-or-index with a default. Only doc_id is left to inference, though its name and schema title make it self-evident.

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 opening sentence, 'Write cells in a Calc document. Returns {written},' uses a specific verb and resource, making the contrast with sibling read_cells obvious (write vs. read). The value/formula entry examples further distinguish it from formatting siblings like style_cells and set_column_width, which target presentation rather than content.

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 thoroughly explains how the tool behaves — entry format, value vs. formula handling, sheet selection — but never states when to prefer it over alternatives such as read_cells for reading or style_cells for formatting. Usage context is implied by the tool's purpose rather than explicitly declared with exclusions or alternative routing.

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