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

Goes well beyond the annotations: discloses irreversibility ('cannot undo it'), the recovery path (correction one invoice at a time), required paid package and payment-status permission, the confirmation policy, the required Cotlet API key, and the return value. This is exactly the kind of extra context annotations cannot carry.

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 core action, then layers behavioral facts in short sentences. The UI-equivalence sentence is slightly redundant with the opening but adds mapping context; otherwise every sentence carries information.

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 correctly states what is returned (the settled invoices), and it covers prerequisites, irreversibility, and confirmation policy. Nothing needed to invoke it safely 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%, so both parameters are already documented. The description adds only the batch nuance that one shared credit date is applied to all invoices, which is a marginal gain over the schema's 'Credit date for all of them.' 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?

States a specific verb and resource with scope: 'Mark several invoices as paid on one credit date,' and clarifies it maps to the UI's 'Bizonylatok kiegyenlítése' bulk action. It is clearly distinguishable as a batch operation, though it never names the sibling single-payment tool (szamlazz-hu_record_payment) as the contrasting alternative.

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?

Gives useful operating context (default per-call confirmation that can be disabled, confirm with the user since it reaches others). However it never states when to prefer this over szamlazz-hu_record_payment or when not to use it, so the selection guidance is implied rather than explicit.

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