imap_download_attachment

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

With no annotations, the description carries the full burden and does well: it discloses type-dependent side effects (images returned inline, PDFs saved plus text extracted, other files written to the shared downloads directory or savePath). Gaps remain around failure conditions (missing attachment), size limits, and permissions, which an undocumented mutation-style tool would ideally state.

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, front-loaded with the action and addressing scheme, then the per-type behavior, then the usage cue. The middle sentence is dense but every clause carries information; no filler sentences.

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?

No output schema or annotations exist, so the description must carry the behavior, and it does explain the differing return shapes by file type plus the disk-write side effect. It is nearly complete for this tool, with only error/permission behavior left unspecified.

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 description coverage is 100%, so the baseline is 3. The description maps some behavior to parameters (filename/contentId, savePath, extractText), but largely restates what the schema properties already document, adding no format or edge-case guidance beyond it.

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+resource combination ('Download a single attachment from an email') with the addressing triple (folder + uid + attachment filename/contentId) and the reference tool for discovery (imap_get_email). An agent can distinguish this from imap_get_email, which returns the body, without opening the schema.

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?

Gives an explicit when-to-use condition: 'Use when the user wants the actual file contents, not just the message body.' This routes the agent away from the body-reading sibling, though the alternative is not named as a fallback tool for the opposite case.

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