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

Adds substantial context beyond annotations: required auth scope, the full allow-list of editable fields, explicit non-actions (no account deletion, no unlinking, no email change), and the conditional tools/list visibility for OpenAI/ChatGPT hosts. The mutation semantics match annotations (readOnly=false, destructive=false), so nothing conflicts.

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-loads the action and scope in the first sentence, then layers auth, allowed fields, and boundaries efficiently. The closing paragraph about ChatGPT tools/list visibility is somewhat meta but short and does explain a host-specific behavior.

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 values need no explanation, and the description covers auth, allowed fields, and mutation boundaries well. It could say a bit more about per-field value formats or failure behavior, but for a 3-parameter preference updater it is nearly complete.

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, and the description earns an extra point by enumerating the permitted field_name values (currency, units, passports, visas, lists.bookmarked, etc.), which the schema only vaguely describes as 'Only traveler profile fields are allowed'.

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 (Update), resource (saved traveler profile preference), and scope (one field, signed-in user). This clearly reads as the write counterpart to the sibling get_profile_preferences, so an agent can route between them without opening either schema.

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 clear preconditions (OAuth 2.0 token with profile.write scope) and explicit scope exclusions (cannot delete the account, unlink messengers, or change email). It stops short of naming when to prefer an alternative tool, but the context needed to invoke it correctly is present.

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