Get MIO Attachment

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

Goes well beyond the readOnly/non-destructive annotations by disclosing two distinct runtime behaviors: in HTTP mode a browser link that expires after 15 minutes, otherwise a local file is written and its path returned. The local-write side effect is important for an agent to know. Minor gap: no indication of where files are saved or what happens on invalid IDs.

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?

Two tight sentences: the primary action and the dual-mode return behavior come first, the prerequisite pointer last. No filler.

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?

With no output schema, the description correctly compensates by describing both possible return values (expiring link vs. local path). Complete enough to call correctly; only error/failure behavior is left implicit.

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% and both parameters carry descriptions, including the origin of attachment_id. The description adds no parameter-level detail beyond the pointer to read-mio-message, so baseline 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?

States a specific verb and resource ('Fetch a MIO message attachment') and immediately disambiguates from the sibling read-mio-message by declaring that tool as the source of attachment IDs. An agent can distinguish it from get-document-link / get-assignment-file-link by the MIO attachment scope.

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 a clear prerequisite path: get attachment IDs from read-mio-message, which is the natural gateway. It does not explicitly say when to prefer this over get-document-link or get-service-link, but the resource scoping makes the choice reasonably inferred.

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