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

Annotations already signal that this is a non-read-only, idempotent, destructive mutation. The description adds useful row-level semantics: only the provided fields change, so omitted values are left untouched. This is beyond the annotation metadata and helps the agent understand partial-update behavior.

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?

The description is compact and front-loaded with the purpose. Every sentence contributes value: when to use it, what can be changed, multiple-in-one-call capability, the partial-update behavior, and a pointer to list_guests. No filler or repetition.

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?

Given the output schema, annotations, and sibling tool listing, the description is operationally sufficient for a straightforward update tool. The main gap is that event_id is a required parameter but not explained in the description, and the consent nuance is only in the schema; still, the pointer to list_guests and the reference to invitation IDs keep the agent from being fully lost.

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?

The description clarifies that multiple guests can be updated at once and maps fields to name, email, and phone, partially compensating for the schema's low 33% coverage. However, event_id is not explained, and host_confirms_sms_consent is only described in the schema, so the description does not fully carry the semantic load for all three parameters.

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 states a specific action — correct or change saved guests — and names the exact attributes affected (name, email, phone). Because it says 'correct or change saved guests,' it is clearly distinct from adding, removing, or listing guests.

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 explicitly scopes when to use the tool ('when the user wants to correct or change saved guests') and tells the agent where to find invitation_ids with lemonvite_list_guests. It does not explicitly exclude use cases like adding or removing, but the trigger condition is clear enough to route correctly.

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