create_customer

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

With no annotations, the description fully explains key behavioral traits: the upsert semantics, matching based on external_source/external_id or name, and that repeated calls never duplicate. It also clarifies that domain is an industry field, not a web domain, preventing misuse. This goes well beyond a simple 'create' statement.

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?

The description is well-structured with a clear upsert warning up front, followed by a detailed but necessary Args list and a Returns statement. Every sentence earns its place; the length is appropriate for an 11-parameter tool with nuanced behavior.

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?

Given the tool's complexity (11 parameters, no annotations, output schema not provided in context), the description covers purpose, upsert behavior, parameter details, and return value. It is sufficient for an agent to use the tool correctly without additional context.

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 0%, so the description must compensate. It does so excellently by explaining each parameter's meaning, including name as a match key, allowed values for stage and contract_status, domain as industry (not web), revenue as a string, and the role of external_source/external_id. This adds significant semantic value beyond the raw schema.

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?

The description clearly states 'Create a customer, or update the existing one it matches (upsert).' This specifies the verb (create/update), resource (customer), and the unique upsert behavior, distinguishing it from sibling tools like update_customer and delete_customer.

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 provides clear context by explaining it is an upsert, not a plain create, and describes the matching logic. However, it does not explicitly mention the alternative update_customer or state when to prefer that tool over this upsert, so it lacks explicit exclusions.

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