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

Annotations already say write, idempotent, non-destructive, and the description independently adds what those annotations cannot: the exact artifacts created, that a repeat call returns the existing record rather than erroring, that lovedOneEmail is never auto-contacted, and that PHI must not be solicited. It even restates 'This is a write' for emphasis, consistent with readOnlyHint=false.

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?

Five front-loaded sentences: purpose, idempotency, precondition, PHI prohibition, then email caveat and the write marker. Everything is load-bearing, though the closing note about lovedOneEmail largely repeats the schema field description and could be trimmed.

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 9 parameters, no output schema, and a multi-step side-effecting operation, the description covers safety, consent, PHI, and idempotency well. It never says what identifiers the successful response returns for follow-up calls (e.g. lovedOneId for list_care_events), which is the main remaining hole given no output schema exists.

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 100%, so the baseline is 3; the description earns above that by adding cross-parameter context the per-field text can't carry, notably that attestAuthorized must be confirmed verbally with the caller before being set and that dateOfBirth is PHI accepted only when volunteered. Minor redundancy with the schema on the email-forwarding and defaulting rules keeps it from a 5.

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?

The description gives a concrete verb and resource ('sets up a loved one on LovedOne') and enumerates the three side effects: workspace creation/addition, @lovedone.app inbox allocation, and attestation recording. It never names the near-miss sibling invite_family_member, so an agent must infer which of the two people-oriented tools applies to a given request.

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?

It states a hard precondition ('confirm attestAuthorized with the user in plain words') and explicit prohibitions ('Do NOT ask for date of birth, medications, or SSN'; dateOfBirth only if volunteered). That is strong when-to-use guidance, but it offers no routing to alternatives such as list_loved_ones or get_onboarding_status when setup has already occurred.

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