download-bytes-to-file

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

Annotations already declare readOnlyHint=true, and the description adds valuable behavioral details beyond that: it returns { path, contentType, bytesWritten } instead of base64, never overwrites existing files, and mentions the stdio/HTTP modes. It does not contradict the annotations.

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 dense but well-organized, front-loading the core purpose and then providing routing guidance and specific constraints. Every sentence contributes value, and the structure is clear despite the length.

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?

The description covers all major use cases (mail attachments, meeting recordings, profile photos, Teams hosted content), explicitly explains the return value, and directs the agent to alternatives for other scenarios. Given the lack of an output schema, it sufficiently explains the output format, making it complete for an agent to decide when to use it.

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 already provides 100% coverage with detailed descriptions for both parameters. The description adds minor context (e.g., a note about meeting recordings and the output format), but this does not significantly extend the parameter semantics beyond what the schema already documents, so the baseline of 3 applies.

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 ('Write'), the resource ('authenticated Microsoft Graph byte content'), and the destination ('local file on the server'), and distinguishes itself from siblings by noting it is the only out-of-band way for mail attachments and meeting recordings, and explicitly compares to get-download-url for OneDrive/SharePoint.

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?

It explicitly states when to use this tool ('The only out-of-band way to save mail attachments and meeting recordings') and when not to ('For OneDrive or SharePoint file content, get-download-url is preferred'), plus it mentions alternative tools like get-meeting-recording-content. This leaves no ambiguity for an agent.

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