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

Beyond annotations (idempotentHint=true, readOnlyHint=false), the description reveals that creation targets the selected business, requires customer-write permission, and that search-before-create is expected; it also clarifies the retry semantics of the idempotency key. This adds meaningful behavioral context without contradicting annotations.

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, with the action and permission scoping first and usage guidance second. No filler or repetition of schema contents.

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 create operation with no output schema, the description covers prerequisites, duplicate avoidance, and retry behavior, which is sufficient for correct calling. It stops short of describing the response shape or error behavior, but for a simple create with 100% schema coverage this is a minor gap.

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?

All 11 parameters are documented in the schema (100% coverage), so the description doesn't need to restate them. It does emphasize the idempotency_key retry rule, but that meaning already appears in the schema description, so the description adds little new parameter-level information.

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 ('creates') and resource ('one customer'), and scopes it to the selected FieldRobin business, which differentiates it from read/search siblings like search-customers and get-customer. The phrase 'directly' clarifies it is not a draft or lead conversion.

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?

Explicitly instructs to search first to avoid duplicates and restricts idempotency-key reuse to retries, giving clear workflow context. It also states the permission prerequisite (customer-write). It does not explicitly name alternatives or conditions where another tool should be used instead, 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.