get_email_attachments

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

With no annotations provided, the description carries the full burden. It clearly communicates a read-only fetch operation and discloses the exact return shape including contentBytes. It does not mention potential caveats such as base64 encoding, size limits, or behavior when the message has no attachments, which keeps it short of a 5.

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 two short clauses with zero filler. The core action is front-loaded in the first sentence, and the compact return-array declaration adds concrete value. Every word earns its place.

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 two-parameter read operation with no output schema, the description is largely complete: it specifies purpose, input, and the exact return structure. It omits minor edge-case details like no-attachment behavior and the encoding of contentBytes, but the field names make those mostly self-evident. No output schema raises the burden slightly, and this description meets it well.

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%, so the baseline is 3. The description adds little beyond schema: it rephrases the id parameter as 'given Outlook messageId' and does not mention the mailbox parameter at all. The schema already documents both parameters adequately, so no deduction is warranted.

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 names a specific verb ('Fetches'), a specific resource ('file attachments'), and the exact input ('given Outlook messageId'). It also distinguishes the tool from all sibling email tools by clarifying that it returns the content of attachments, not emails or folders. No sibling covers attachments, so no ambiguity remains.

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 a clear context: use this tool when you need the actual attachment content for a particular Outlook message. It does not state any exclusions or alternatives, but none of the sibling tools handles attachments, so no routing guidance is necessary. Lacks explicit when-not-to-use statements, preventing a 5.

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