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

The description discloses important behavioral traits beyond the annotations: idempotency (matching annotation), URL expiry (≤60 seconds, never after inbox expiry), the trust caveat (clean verdict does not make content trusted), and the transport instruction (lease bearer on HTTP/MCP, never in arguments). These add significant value beyond the idempotentHint and openWorldHint 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 three sentences, each densely informative: the main action and condition, the expiry/trust caveats, and the transport instruction. It is front-loaded with the core behavior and contains no fluff.

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?

Given that an output schema exists (return format is already covered), the description covers all operational essentials: the active-inbox precondition, the safety-verdict condition, expiry behavior, the trust caveat, and the lease-bearer transport requirement. An agent has everything needed to invoke it correctly.

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 0%, so the description carries the full burden of explaining parameters. It does not mention inbox_id, message_id, attachment_id, or idempotency_key at all. The schema itself provides names and patterns, but the description adds no semantic meaning, leaving the agent to infer from names alone.

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 states a specific verb (return) and resource (download URL for an attachment) with a precise condition (only when the exact stored attachment has a clean safety verdict). It clearly distinguishes this from sibling tools like ausca_artifact_access by scoping it to inbox attachments and the safety gating.

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 provides clear context for when to use the tool ('For an active inbox') and the condition of a clean safety verdict, but it does not explicitly name alternatives or state when not to use it. The context is sufficient for an agent to decide, though exclusions are absent.

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