open_workbook

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

No annotations are provided, so the description carries the burden. It states 'in-place worksheet editing', which implies the tool modifies the workbook directly. However, it does not disclose whether it requires specific permissions, locks the file, or how it handles unsaved changes. The behavioral transparency is adequate but not thorough.

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 a single, front-loaded sentence that clearly states the purpose. Every word is necessary, with no filler or redundancy.

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 that there is an output schema (not shown but present) and a single parameter, the description is minimally adequate. However, it lacks context about what happens after opening (e.g., if the workbook is loaded into memory, if subsequent tools operate on it) and does not mention prerequisites like file existence or format validity.

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%, but there is only one parameter (file_path). The description adds no additional meaning beyond the parameter name; it does not specify path format, allowed file extensions (though implied), or whether absolute/relative paths are accepted. With low coverage, the description should compensate but does not.

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 verb 'Open' and the resource 'existing workbook', specifying file types (.twb or .twbx) and the purpose 'for in-place worksheet editing'. It distinguishes this from sibling tools like 'create_workbook' or 'save_workbook' by focusing on opening an existing file.

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 implies usage when you need to edit worksheets in an existing workbook, but it does not explicitly state when not to use it or provide alternatives. Among many sibling tools, it doesn't clarify that for creating new workbooks one should use 'create_workbook' or for saving use 'save_workbook'.

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