Delete custom field

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

Annotations already carry the safety profile (destructiveHint=true, idempotentHint=true), so the bar is lower; the description still adds genuinely new context: the blast radius ('from every contact', values included), a downstream side effect on segments, and an expected return value.

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?

Four bold-labeled blocks, front-loaded with purpose, each sentence carrying distinct information (scope, alternative, return, precondition). 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?

For a one-parameter destructive tool with no output schema, the description covers what it does, what it is not for, the return value, and the precondition check — everything an agent needs to call it correctly and safely.

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 a single documented parameter, so baseline 3 applies. The description implies the 'field' argument is a field key/name but adds no syntax, casing, or ID-vs-name guidance beyond what the schema supplies.

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 verb and resource ('Remove a custom field and its values from every contact') and immediately distinguishes it from the closest sibling by naming plunk_update_contact for per-contact clearing. An agent can tell it apart from plunk_list_contact_fields, plunk_get_field_usage, and plunk_delete_contact with no schema inspection.

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?

Explicit when-not ('Not for: Clearing it on one contact — pass null for that key via plunk_update_contact instead') paired with an explicit when ('A field is genuinely obsolete'), plus a named prerequisite (plunk_get_field_usage) and a stated exclusion scenario (segments filtering on it will stop matching).

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