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

Annotations already cover readOnly, idempotent, and non-destructive, so safety is settled. The description adds genuinely new behavioral facts: the tool never fans out across Locations and a single `location` is required when the connection has multiple (pointing to list_locations). Neither fact is derivable from the annotations or schema.

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 purpose and the download_attachment hand-off are front-loaded and waste-free. The trailing admonition paragraph is slightly verbose for a single constraint but still earns its place by preventing a common misuse.

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 an output schema present, return values need no explanation, and the multi-location constraint plus the FileID hand-off are the key operational gaps this tool has. The only remaining omission is guidance on `limit` and `transaction_id`, which is minor against an otherwise complete operational picture.

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 0%, so the description must compensate, and it partly does by mapping prose concepts to parameters (date range → start/end_date, vendor → payee, card → credit_card_id, location → Location ID). However, `limit` and `transaction_id` are never mentioned, and no format hints (dates, amount semantics) are given for an all-optional, default-heavy parameter set.

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 and resource — list invoice/receipt scans attached to CREDIT CARD transactions — and explains the unique niche: card purchases carry attachments on the card transaction rather than an AP bill, putting them outside the bill and check tools. That contrast alone separates it from get_bills and get_check_attachments without opening either schema.

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 concrete search strategy (by date range, vendor, amount, or card) and an explicit next step: pass a FileID to download_attachment to read the document. The bill/check comparison implicitly excludes those siblings, but there is no explicit 'do not use this when…' statement.

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