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

Annotations already declare readOnlyHint/openWorldHint=false/destructiveHint=false, so the safety profile is covered. The description adds real behavioral context: the OneDrive-mount scoping requirement and the performance advantage over listing a directory. It could note whether missing paths error vs return empty, but the added context is solid.

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 sentences, all front-loaded and information-dense: what it returns, the scoping constraint with a pointer to onedrive_root, and the efficiency rationale. No filler.

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?

Low-complexity single-param read tool with a rich output schema (so return values need not be described), full schema coverage, and annotations covering safety. The mount constraint and alternative routing make the definition complete for correct invocation.

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 coverage is 100% (baseline 3), and the description still adds meaning beyond the schema's 'Absolute path': the path must reside under a OneDrive mount. This constraint is not derivable from the schema alone.

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?

States a specific verb and resource ('Returns metadata for a file or folder in your OneDrive synced folder') and enumerates the returned fields (size, modification date, type, extension). This clearly separates it from siblings like onedrive_list_files (enumeration) and onedrive_read_file (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?

Explicitly routes the agent: paths must be under a OneDrive mount (pointing to onedrive_root), and 'for other folders use the file tools.' It also justifies choosing it over listing the parent directory when only one item's info is needed. No explicit exclusion list beyond that, so not a full 5.

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