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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered structurally. The description adds the concrete endpoint mapping and the payment_status applicability constraint, which is genuine extra context, but says nothing about pagination, result volume, or sort defaults. With annotations shouldering the behavioral load, this is adequate but thin.

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 compact sentences: the resource enumeration comes first, then the invoice carve-out, then the filter constraint and endpoint. No filler, and the most decision-relevant information (which types, which sibling) is front-loaded.

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?

Ten parameters with only one required, and the description correctly focuses on the tool's only real ambiguity: which document type and how it splits from the invoice tool. With 90% schema coverage and no output schema, the remaining gaps (return shape, ordering defaults) are minor, though it doesn't hint at what a list reply contains.

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 90%, so nearly every parameter is self-documented, establishing a baseline of 3. The description restates payment_status scope, which the schema already states, and adds no filtering semantics for search, status default, or date range beyond what the schema provides. No added value over structured 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 (list) and enumerates exactly which resources are covered (quotes, orders, delivery_orders, credit_notes, payments, refunds), and explicitly carves out invoices as belonging to the sibling bukku_list_sales_invoices. An agent can distinguish this from bukku_list_sales_invoices and bukku_get_sales_document without opening a 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?

Names the alternative tool for invoices explicitly and states the routing condition (invoices have their own tool). It also scopes payment_status to only credit notes, payments and refunds, telling the agent when not to pass that filter. A clear when/when-not/alternative set for a list tool.

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