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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description reinforces this with 'it does not pay anyone' and adds genuinely new context: the auth requirement ('Cotlet API key with access to this app') and a domain invariant ('amount owed up to today is never lower than the amount due for the period').

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-loaded with the key figures, but the description restates the same 'amount due for the period / amount owed up to today' pair twice in consecutive sentences. Tighter wording would carry the same information with less repetition.

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 takes on the job of explaining the return shape (per-provider, two figures) and does so adequately, plus it covers the auth prerequisite. Nothing essential for correct invocation is missing.

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% and both required date parameters are documented with clear descriptions in the schema. The description only refers to 'the pay period you give' without adding format or boundary details beyond the schema, so 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 ('Amount due per provider for a pay period and amount owed up to today') and pins the exact two figures returned. It is clearly distinguishable from the BookingKoala siblings, which handle bookings, invoices, charges and provider lists.

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?

Tells the agent it maps to 'Provider Payments in BookingKoala' and clarifies it does not pay anyone, which steers away from any payout action. It gives clear context but no explicit when-to-use vs a named alternative (none exists among the siblings).

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