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

The only annotation is destructiveHint=true, which is a weak safety signal for an additive create. The description usefully discloses the side effect that an invitation email is sent by default and how to suppress it, plus the endpoint. It stops short of stating auth/permission needs or whether the created profile is immediately active.

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 sentences, front-loaded with the core action, then the default behavior, then the endpoint. No filler; every clause carries 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?

For a create tool with no output schema, the description covers the action, the primary side effect, and the opt-out. It leaves unspecified whether a customer identifier is returned and whether email is required for the invitation path, minor gaps given the rich schema.

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 already 100%, so the schema documents each field. The description still adds interpretive value by explaining the default and the effect of send_invitation_email=false ("add them silently"), clarifying intent beyond the schema's terse "TeamUp default: true."

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 ("Add a new customer"), reveals it is created "as staff," and even names the underlying endpoint (POST /customers). This is clearly distinguishable from siblings like get_customer and list_customers.

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?

Explains the default behavior (invitation email sent) and how to override it (send_invitation_email=false for silent add), which is the key decision an agent faces when calling this tool. It does not, however, name sibling alternatives or state when this is preferable to register_customer_for_event.

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