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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description goes well beyond by disclosing that a created payslip is always a draft, an edit never flips the draft flag, and the operation never posts to the ledger. It also documents the two refusal scenarios, which is exactly the behavioral context an agent needs before calling.

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, no filler, and the create-vs-edit rule is front-loaded ahead of the caveats. Every clause adds a constraint an agent needs.

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 mutation tool with no output schema, the description covers the critical safety and workflow context (draft-only, no ledger posting, refusal conditions). The remaining gap is input detail — the line object's structure and field formats — which neither the schema nor the description clarifies.

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?

With 0% schema description coverage the description must carry the load, and it names the core inputs (employee, pay run, period, pay date, lines, id semantics) plus the earning/deduction/contribution line concept. However, it says nothing about the `notes` field, the line sub-fields (code, role, amount, quantity, statutory, sort, etc.), or the date/number formats, so 8 parameters are only partially explained.

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(s) and resource (create/edit a DRAFT payslip) and enumerates the entity's scope: employee, pay run, period, pay date, earning/deduction/contribution lines. The create-vs-edit distinction via 'id' is stated explicitly, so it is distinguishable from siblings like finalise_payslips and get_payslip.

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 explicit routing rules: omit id to create, pass id to edit. It also states two exclusion conditions — a finalised payslip refuses an edit, and a payslip on a self-finalising pay run is refused — so the agent knows when the call will fail.

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