excel_open

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

With no annotations, the description carries the full burden of behavioral disclosure, but it only states 'Open... inspect metadata' without explaining side effects, file locking, or that read_only defaults to false. It doesn't clarify whether the file is modified or what state the workbook is left in after opening.

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?

One concise sentence with no filler, front-loading the action and resource. Every word contributes to the tool's purpose.

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 simple two-parameter tool with an output schema and full schema coverage, the description is minimally viable. However, it doesn't address when read-only mode matters or how this relates to excel_inspect and subsequent excel_read_range calls, so an agent may still be uncertain about workflow placement.

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?

The input schema covers both parameters with descriptions, so schema coverage is 100%. The description adds no additional parameter meaning beyond the schema, but it doesn't need to.

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 uses a specific verb ('Open') and resource ('existing Excel workbook') and adds 'inspect metadata,' which clarifies the tool's scope. It distinguishes itself from create/export/read siblings by action, though it doesn't explicitly separate itself from the similarly named excel_inspect tool.

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 is provided on when to use this tool versus excel_inspect, excel_read_range, or how it fits into a workflow. The description gives no exclusions or alternatives, leaving usage entirely to inference.

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