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

With no annotations, the description carries the full burden and does: it declares the auth requirement (login token or bound cloud-market credential), the failure modes (401 when unauthenticated, code=40003 with data.bindUrl when the instance is unbound), and a downstream behavioral constraint (no profile save until a candidate is chosen).

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?

Front-loaded with the action and scope, then a compact auth block. Dense but every sentence (trigger, candidate rule, auth, error codes) earns its place; only slight cost is the mixed imperative/ontology phrasing.

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?

No output schema and no annotations, yet the description still covers auth, error surfaces, and candidate-resolution flow. The main gap is the return shape — it implies a contactid field but doesn't state what each contact record contains, which matters for the follow-up contact_profile_save flow.

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 0%, so the description must compensate; it says gender and relation are filters over the current user's contacts, which is more than the bare schema offers. However it gives no accepted values, casing, or whether both filters combine (AND) — an agent still can't construct valid values reliably.

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+resource: query the current user's contacts filtered by relation/gender, plus an ontology line (contact → list). It is clearly a list operation and separable from contact_get/profile_get siblings, though it never names the alternatives (corp_contact, contact_get) explicitly.

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 an explicit trigger ('用户提到家人时必须先调用') and resolution rules: a single candidate may use contactid directly, multiple candidates require user selection, and profile saving is forbidden until selected. What's missing is when NOT to use it versus contact_get or corp_contact for non-family/company contacts.

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