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

Goes well past the annotations (readOnly false, destructive false, non-idempotent) by disclosing all-or-nothing atomicity ('checked whole; refused whole'), that failures name the offending row and the fix, the 200-row ceiling, and the exact write effect ('status, category, vendor recorded on every row listed'). The confirmation-as-reason requirement adds audit context an agent could not infer.

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?

Front-loads the core action and consequence ('Checked whole; refused whole') before the workflow and field rules. Slightly repetitive — the refuse-whole guarantee is stated twice ('refused whole' up front, then again in the validation sentence) — but every other clause carries distinct instruction.

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 non-read-only batch mutation with no output schema, it covers the prerequisite read, the propose-then-confirm protocol, per-row validation and rejection semantics, the size limit, and the resulting effects. An agent has enough to invoke it correctly and to explain a refusal without further documentation.

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 100%, so the baseline is 3, but the description adds genuine field-level meaning: a recurring row must carry its vendor and naming it is what declares the subscription, and a transfer's category is the counterparty account rather than a spending category. These are semantic rules absent from the schema text.

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?

Names a specific verb and scope: review a whole statement in one act, setting status, category and vendor per row plus one reason. The phrase 'a whole statement in one act' plus the 'Up to 200 rows' cap implicitly separates it from the single-row sibling purch_review_transaction, but that sibling is never named, so the differentiation is inferred rather than stated.

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 a strong explicit workflow: read purch_vocabulary first for statuses/categories/vendors, propose for every row, show the whole table to the person, and write nothing until they answer. It also states exclusions ('a row you cannot name stays out of the batch'), but it never names an alternative tool for the single-row or partial case.

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