create_contact

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

With no annotations, the description does carry the main behavioral fact: the call is effectively idempotent and will return an existing record rather than duplicating. It says nothing about required permissions, what happens on invalid email, or partial/match semantics — gaps that matter for a write tool with zero annotation coverage.

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 short sentences, zero filler, with the outbound behavior and the workflow ordering both front-loaded. Nothing could be cut without losing 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?

An output schema exists so return shape needn't be explained, and the sibling reference covers workflow placement. But for a 2-parameter write tool with no annotations and no schema descriptions, the absence of any parameter or failure-mode detail leaves the definition thin.

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 and does not: neither email_address nor full_name is mentioned, and it never states that email is the identity key or that full_name is optional. The only hint is the word 'sender', which loosely implies email.

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 contact') and adds a key behavioral qualifier ('or return the existing one'), which signals an upsert rather than a plain insert. It does not explicitly name find_contact as the counterpart, so the differentiation from that sibling is only implied.

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?

Gives a clear precondition: 'Needed before escalate_to_human when the sender is not yet in the CRM.' That tells the agent both the trigger and the ordering constraint. It stops short of saying 'use find_contact instead if the sender already exists', leaving the when-not case to inference.

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