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

Goes well beyond the annotations: discloses that the job is asynchronous with a call_id and download link per part, that credentials are excluded, that parts are decryptable only by this key and by owner/admin keys with sufficient permissions, and that a non-company team key gets owner_required. It also warns that the owner is emailed and that free-tier quotas apply, so the agent knows the side effects of a non-readOnly, non-idempotent call.

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 content is front-loaded and useful, but there is real duplication: 'Free' is stated twice and the background/polling instruction is given twice with different wording ('poll the call with account_get_call; the result has a download link for each part' vs 'the reply has a call_id; poll it with the account_get_call tool or GET /v1/calls/<id>'). The garbled sentence about which keys can open the parts also costs clarity.

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 zero-parameter, no-output-schema job tool, the description carries the burden well: it explains what is produced, how to retrieve it, and what access and quota rules apply. It omits retention/expiry of the download links and leaves the key-permission rule phrased ambiguously, which is the only gap.

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?

The tool takes zero parameters, so there is nothing to disambiguate and the baseline of 4 applies. The description correctly offers no parameter discussion.

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 with precise scope: everything the account holds, as JSON Lines per area plus stored files, in ZIPs up to 24 MB written to the file store. That scope distinguishes it from the narrower account_export_person and books_export siblings without needing to name them.

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 clear operating context: it is an asynchronous job, you must poll with account_get_call, and it is rate limited to one at a time and three per day. It never explicitly routes the agent to account_export_person or books_export for narrower exports, so the alternative-selection guidance is implied only by scope.

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