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

Annotations already declare this is a non-readonly, non-idempotent, non-destructive mutation. The description adds valuable behavioral detail beyond annotations: each line is processed independently, only successfully matched lines are charged, pricing is $0.02 per matched bank line, and unmatch reverses account-booked lines.

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 front-loaded with the core action and then enumerates the modes efficiently. It is somewhat run-on and could be easier to scan as a structured list, but for a complex batch tool it remains dense without much wasted text.

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 complex batch mutation with no output schema and only basic annotations, the description covers modes, partial success, charging, and reversal. It is still missing explicit prerequisites such as where line_id comes from and a clearer statement of what the per-line success/failure response looks like.

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 low, so the description must carry parameter meaning. It does well for the core mode fields by explaining entries, invoices, bills, account, rule, ignore, and unmatch, and it clarifies that invoice/bill amounts are spread in order unless explicit amounts are supplied; however, it does not explain line_id, tax, rate, tracking, or description fields.

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: matching bank lines, up to 100 at a time. It also enumerates the possible per-line actions (entries, invoices, bills, account, rule, ignore, unmatch), making the tool's scope distinguishable from generic bank-line listing or rule application.

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?

The description explains what each match mode means, which implies how to choose among them, but it never explicitly says when to use this tool versus siblings such as books_bank_lines or books_apply_bank_rules. It also does not state the prerequisite that line_id values come from listing bank lines.

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