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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description reinforces the write nature with 'WRITE:' and the HTTP verb, but adds nothing about duplicate handling (relevant given idempotentHint=false) or what is returned on success.

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?

One compact sentence plus an endpoint reference, with the write nature and required fields front-loaded. Nothing is padded or redundant.

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?

Not applicable — see below.

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 coverage is 50% — email, phone, and mobile have no schema descriptions. The description compensates partially by restating which fields are required (firstname, lastname) and which are optional, but gives no format or constraint hints beyond the field names, which the schema's required array already conveys.

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 customer in the CRM') and even names the underlying endpoint (POST /customers). Against siblings like update_customer, get_customer, and list_customers, the verb alone lets an agent route correctly without opening any schema.

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 'WRITE:' prefix and the create verb imply when this applies, but there is no explicit guidance on alternatives or preconditions — nothing about checking list_customers/get_customer first to avoid duplicates. Usage is inferable but not stated.

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