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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds value beyond that by enumerating returned content (lines, total, balance, status), noting 'the total is the sum of the lines', and disclosing an auth requirement ('Cotlet API key with access to this app'). That is meaningful behavioral context for a read tool.

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?

The tool is front-loaded correctly, but the opening sentence ('Acumatica: One AR invoice with its lines, total, balance and status') is almost fully restated by the next sentence ('Returns one AR invoice with every line... the total and the status'), which is wasted duplication.

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 single-parameter read tool with no output schema, the description does the necessary work by describing the payload an agent will receive and the auth prerequisite. Nothing essential is missing, though it could be tighter.

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 the single parameter's provenance ('from list_invoices or list_bills') is already documented in the schema. The description adds no syntax or format detail beyond that, 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?

The description states a specific verb+resource ('Returns one AR invoice with every line... the total and the status'), making it clearly distinct from the singular/plural split with acumatica_list_invoices. It does not explicitly name that sibling, but the scope ('one AR invoice') is unambiguous.

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?

It gives a concrete usage context: 'Use it to check an invoice you just created before releasing it', which ties the call into the create→verify→release workflow. It stops short of naming alternatives or stating when not to use it, so it falls short of a 5.

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