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

Beyond the annotations (readOnlyHint=false, idempotentHint=true, openWorldHint=true), the description adds meaningful behavior: the URL lives at most 60 seconds and never past inbox expiry, a clean verdict does not imply trusted content, and the lease bearer must travel on the HTTP/MCP transport rather than in arguments. These are non-obvious operational and security constraints that go well past what the structured fields convey.

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 core action is front-loaded in the first sentence, followed by expiry, trust caveat, and auth transport in tight succession. It is dense but every sentence carries distinct information, with little waste.

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?

An output schema exists, so return values need not be described, and the annotations cover the safety profile. The description is strong on behavior and security but leaves the four parameters substantially under-explained, which is the main remaining gap for a gated access-minting tool.

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% across 4 required parameters, so the description carries the full explanatory burden. It only obliquely evokes the parameters ('active inbox', 'exact stored attachment', 'idempotent') and never states what the idempotency key does, why it is required, or what message_id versus attachment_id mean; the JSON-schema patterns are the only format guidance.

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 operation (return an idempotent download URL for a stored attachment) and its gating condition (clean safety verdict on an active inbox). It is clearly scoped apart from read/status siblings, but it does not name or differentiate itself from nearby tools like ausca_artifact_access or ausca_agent_inbox_read, so sibling differentiation is only implicit.

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 states preconditions for a successful call (active inbox, exact stored attachment, clean verdict) and gives auth guidance (supply the lease bearer on the transport, never in arguments). However it never says when to choose this over the artifact-access or inbox-read alternatives, so usage is implied rather than explicit.

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