open_workbook

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

With no annotations, the description covers key behaviors: the file is opened for editing, a session_id is returned, changes are held in memory until saved, and an absolute path is required. Missing error handling details but sufficient.

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?

Three concise sentences, each adding value: purpose, return value/memory behavior, and path requirement. No unnecessary words. Front-loaded with 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 open tool with one parameter and no output schema, the description covers purpose, return, state management, and a usage hint. It is complete enough for an AI agent to invoke correctly.

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 schema has no description for the 'path' parameter, but the description adds crucial context: it must be an absolute file path and points to an existing file, which compensates for the 0% schema coverage.

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 opens an existing .xlsx or .xlsm file for reading and editing, and its return of a session_id distinguishes it from siblings like create_workbook and close_workbook.

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 provides context: changes are in-memory until save_workbook, and to use an absolute path. However, it does not explicitly mention when not to use this tool or name alternatives like create_workbook.

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