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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds that results carry opt-out and primary/billing/pickup flags and the backing endpoint, but says nothing about pagination behavior or result size limits beyond what the schema already documents.

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?

A single front-loaded sentence enumerating the return fields plus the endpoint path — efficient and scannable. The field list is dense but each item conveys real information about the payload.

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?

With no output schema and 11 optional filters, the enumeration of returned fields (name, type, email, phones, address, flags, opt-outs) is genuinely necessary and present. What is missing is sibling disambiguation and any note on pagination/incremental sync usage, which the schema alone covers only partially.

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% with 11 parameters, so the baseline is 3. The prose only mentions the 'authorized-for-pickup' flag and does not explain the filtering dimensions (email, phone, updated_since, family_id/member_id) or how they combine, adding little beyond the schema.

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?

Specific verb (List) plus resource (family contacts / GET /v1/Contacts) with an enumerated set of returned fields, so the agent knows exactly what data comes back. It does not, however, distinguish itself from the closely-related jackrabbit_list_authorized_contacts or jackrabbit_get_contact siblings.

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?

Usage is only implied by the word 'List' and the 'family contacts' scope; there is no explicit statement of when to pick this over jackrabbit_list_authorized_contacts (which is essentially the authorized=true subset) or jackrabbit_get_contact for a single record. An agent must infer the choice from sibling names alone.

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