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

With no annotations present, the description carries the full burden. It does disclose a meaningful side effect — that a new supplier record is created automatically when supplier_name plus address fields are supplied — which the agent would otherwise have to infer from the schema. It says nothing about permissions, validation failures, whether duplicates are rejected, or what the call returns.

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 short sentences with no filler: the purpose leads and the supplier-identification rule follows immediately. Nothing in it is wasted, though it is arguably a touch thin for a multi-parameter mutation tool.

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 zero annotations and no output schema, the description should say more. It covers the one non-obvious behavior (supplier auto-creation) but leaves required-field expectations, failure modes, and return shape unaddressed.

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 description coverage is 100%, so the schema already documents all 11 parameters, including the supplier_id-takes-priority rule and the address/city/country requirement for auto-creation. The description restates this logic at a high level without adding format, ordering, or edge-case detail beyond the schema, 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?

States a specific verb and resource: 'Create a new supplier proforma invoice.' The 'supplier' qualifier implicitly separates it from the sibling create_proforma_invoice, but the description never makes that distinction explicit.

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?

The description distinguishes the two supplier-identification paths (existing supplier_id vs. on-the-fly creation via supplier_name + address), which is useful routing guidance. It offers no guidance, however, on when to choose this tool over create_proforma_invoice, create_supplier_invoice, or create_simplified_supplier_invoice.

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