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

Annotations only carry destructiveHint=true (a questionable fit for a create), so the description must carry the behavioral load. It usefully discloses that CustomerCode must be unique and is immutable after creation, but says nothing about what the call returns, how uniqueness violations surface, or side effects.

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?

Three short, front-loaded sentences with zero filler: the action first, then the key constraint, then the API mapping. Every sentence earns its place.

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 12-parameter mutation with no output schema and only a single annotation, the description covers the essentials but leaves gaps: no return value, no error/uniqueness-failure behavior, and no permission context. Adequate but not complete.

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 all 12 parameters including the required customerCode/customerName are already documented. The description's only parameter-level note (CustomerCode uniqueness/immutability) largely duplicates the schema description, adding no new syntax or format detail.

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 customer') and identifies the underlying API call (POST /Customers). This cleanly distinguishes it from siblings like unleashed_create_product and unleashed_create_sales_order by resource.

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?

There is no guidance on when to use this versus the get/list customer tools, no mention of prerequisites or permissions, and no exclusions. The uniqueness constraint on CustomerCode is stated but framed as a data rule, not usage guidance.

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