Evaluate a formula

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds useful context: 'Changes nothing', 'Uses pyOfficeEditor's formula engine, 493 of Excel's functions', and 'with the workbook's cells as they stand'. It also clarifies that the result matches what Excel would give. This adds value beyond the annotations without contradicting them.

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 well-structured. It opens with the primary purpose, includes a concrete example, and covers key details (engine, non-destructive, supported file types) without redundancy. Every sentence adds value, and it is not overly long.

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 the output schema exists (not shown but indicated), the description need not detail return values. It covers the tool's purpose, use cases, non-destructive nature, supported formats, and function count. This is sufficient for an agent to decide to invoke it, though it could mention any error handling or edge cases.

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 100%, so the schema already documents all four parameters. The description does not add significant new meaning beyond the schema, though it does hint at the 'at' parameter's role in relative references. Since the schema carries the load, a baseline score of 3 is appropriate.

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's purpose: it evaluates a formula in a cell context without writing it, distinguishing it from write operations. It gives a concrete example (SUMIFS) and names the specific action ('works out what a formula would give'). It differentiates from siblings by mentioning 'without writing it there' and references xlide_write_cells.

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 explicitly states when to use the tool: 'to check a formula before xlide_write_cells, or to ask the workbook a question'. It also implies the tool is non-destructive and works on the current state of the workbook. This provides clear context for an agent to decide when to invoke it versus alternatives.

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