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

Beyond the readOnly/openWorld annotations, it discloses two real behavioral traits: the performance pitfall of unbounded date ranges on busy shops and the fact that paging is done via next_query from the prior reply. It does not discuss rate limits or result volume, but the annotations already cover the safety profile.

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?

Four short sentences, front-loaded with the resource and filter surface, then the date-range warning and pagination note, then the endpoint. Nothing is redundant or padded.

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 10 optional params and no output schema, the description usefully previews the returned shape (amounts, payments, cart items) and covers pagination, which is what an agent needs to call it correctly. It stops short of explaining how to follow the next_query chain or what to do when no date range is known.

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 100%, so every parameter already carries meaning in the schema; the description's parenthetical list of filter dimensions largely restates them. No extra syntax or constraint detail is added, so the baseline 3 applies.

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 ('List sales and other register transactions') and enumerates the filterable dimensions (type, date, branch, register, staff, customer). It implicitly contrasts with the single-record sibling tillhub_get_transaction by being a list, but never names any sibling such as tillhub_transactions_report or tillhub_list_orders.

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?

'Always pass a date range for busy shops' is a concrete usage rule and 'Page with next_query' implies the iteration pattern, but there is no explicit when-to-use-this-vs-alternatives guidance despite many overlapping siblings (reports, aggregates, receipts, orders).

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