m365_files_read

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

Annotations already declare the operation read-only, idempotent, and non-destructive, covering the safety profile. The description adds useful constraints (text-only, 50KB default limit) but does not disclose behavioral details like truncation vs. error for oversized files or encoding handling.

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?

A single, tight sentence with the verb front-loaded. No filler or redundant explanation—every word adds value.

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 read tool with rich annotations, a clear description, and full schema coverage, the definition is largely complete. It falls short only in not clarifying behavior when content exceeds maxBytes (truncation vs. failure), which is a minor gap.

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% for both parameters (itemId, maxBytes), so the baseline is 3. The description reinforces the maxBytes default and text-only constraint, but it does not add much beyond the schema for itemId; the schema already explains its origin.

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 ('Read') and resource ('file's content'), immediately clarifying the tool's function. It also distinguishes from siblings like m365_files_info (metadata) and m365_files_list (listing) by focusing on content retrieval. Constraints (text only, 50KB) further sharpen the purpose.

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 for reading text file content and notes size limitations, but it does not explicitly mention when to prefer this tool over alternatives or give exclusions beyond 'text files only.' No sibling tool is referenced, so the guidance is implicit rather than explicit.

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