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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful non-obvious behavior: the returned TempDownloadUri is a short-lived download link to the original file, which warns the agent the URL cannot be stored or reused.

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 sentences, both earning their place: the first establishes the operation and the selection condition, the second flags the one return-value gotcha. Front-loaded with 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?

For a two-parameter read with no output schema, the description covers the identity lookup, the company-scoping precondition (via schema), and the key returned field's lifetime. It does not describe the rest of the attachable payload, but the notable behavioral detail is present.

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%: both 'id' (QuickBooks Id of the Attachable) and 'company' (name, realm id, or connection id; optional with a single company) are documented in the schema. The description adds no syntax, format, or fallback detail beyond that, so the 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?

The description names a specific verb and resource ('Get a single attachable from QuickBooks Online by Id'), so the agent knows exactly what it returns. It hints at sibling routing via 'when no search or write answer already holds it,' but never names search_attachables, so differentiation is implied rather than explicit.

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 gives a clear precondition for use: only when no search or write response already holds the record, which implicitly routes the agent to search_attachables first. There are no explicit exclusions or error cases, but the 'when' condition is stated rather than left to inference.

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