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

No annotations are provided, so the description carries the full burden. It discloses supported file types (text, CSV, JSON, HTML, code, images) and how they are returned (as themselves or as pictures), and notes limitations. It does not mention permission or error behavior, but the main behavioral traits are covered, making this above average.

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 tightly written with no redundancy. The main verb-action is front-loaded, and each sentence adds distinct information (types, refusal, exceptions, source of id). It is appropriately concise for the complexity.

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 there is no output schema, the description explains what the tool returns for different file types, which is sufficient for an agent to know what to expect. It also covers the main unsupported cases. Minor gaps remain for unspecified binary or unknown file types, but overall it is complete enough for a file-reader.

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 50%; the mailbox parameter already has a description, but itemId does not. The description compensates by indicating that the id comes from list_onedrive_items or search_onedrive_items, which is valuable context. While it doesn't elaborate on the itemId format, the guidance on its source adds meaningful semantics beyond the bare schema.

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 opens with a specific action 'Open one file and return what is in it' and clearly defines the resource (a file from OneDrive). It also distinguishes itself from related tools by explicitly naming read_excel_range as the alternative for Excel workbooks, making its scope unambiguous.

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?

Provides explicit usage guidance: states that Excel workbooks should be handled by read_excel_range, that PDFs and Word documents are not supported, and instructs the agent on where to obtain the required itemId (from list_onedrive_items or search_onedrive_items). This covers both when to use and when not to use, plus prerequisites.

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