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

Adds significant context beyond annotations: it discloses the non-idempotent nature (at most once), the reconciliation risk of duplicates, the creation flow through core's API, and explicit effects ('core customer created; account.customer_id linked'). It does not contradict 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?

The core purpose is front-loaded, but the description is verbose and uses metaphorical language ('a reconciliation problem wearing a convenience', 'where this area's job ends and order-to-cash begins') that could be trimmed without losing essential information.

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 complexity (a mutation that bridges two domains) and the lack of an output schema, the description covers when to use, key constraints, and effects. It could specify return values or error behavior, but the essential invocation details are present.

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 fully documents all parameters. The description does not add any parameter-specific meaning beyond what the schema already provides.

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 the core customer from a won account'. It distinguishes from siblings by specifying the precondition 'Won accounts only' and the once-only constraint, which likely differentiates it from core_create_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?

Provides clear when-to-use context ('Won accounts only, at most once') and implicitly when not to use (non-won accounts or already promoted). However, it does not name alternative tools like core_create_customer for non-won scenarios.

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