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

The readOnlyHint annotation already establishes this is a safe read. The description adds useful context beyond that: the default sort order (newest first) and the shape of returned rows (number, date, customer, status, total). It says nothing about pagination or limits, which matters for a 13-parameter list tool with a 500-row cap.

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?

Two sentences, front-loaded with the resource definition and closed with ordering and return fields. The trailing raw endpoint 'GET /order/list.json' is the one element that does not earn its place for an agent choosing a tool.

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 no output schema, the description compensates by listing the returned row fields, and the safety profile is covered by the readOnlyHint annotation while all 13 parameters are documented in the schema. The remaining gap is pagination behavior (start/limit interplay, the default period scoping of fiscal_period_id), which an agent may need for a list endpoint capped at 500 rows.

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 (dir, sort, type, limit, query, start, filter, only_open, only_overdue, person_id, status_id, category_id, fiscal_period_id) is already documented in the schema, several with cross-references to sibling list tools. The description adds no parameter detail, so the baseline 3 is appropriate.

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 names the specific resource (sales/purchase documents) and enumerates the concrete document types it covers (quotes, order confirmations, invoices, delivery notes, credit notes, vendor bills) plus the fields returned. This is clearly distinguishable from siblings like cashctrl_get_order (single record) or cashctrl_list_journal, though it never states the verb 'list' explicitly and relies on the title for that.

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?

There is no when-to-use guidance: nothing tells the agent when to pick this over cashctrl_list_journal, cashctrl_list_order_categories, or cashctrl_get_order for a single document. 'Newest first' hints at a default ordering but is not usage guidance, and 'GET /order/list.json' is an implementation detail rather than a selection criterion.

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