Create Custom Field

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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true), so the safety bar is lower. The description's only added behavioral context is the deprecation lifecycle status, which is genuinely useful but is not accompanied by any note on side effects, uniqueness constraints on labels, or what a repeated call does.

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?

Two short sentences with the deprecation warning front-loaded, which is exactly the right ordering for a deprecated tool. The only waste is the redundant "from provided data" clause.

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 needn't be described, and the deprecation notice covers the biggest risk. However, for a nested-object mutation tool with 0% top-level schema description coverage, the description leaves the caller to reverse-engineer the `data` envelope entirely from the schema.

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 reported as 0% at the top level, and the description says nothing about the single `data` parameter — no mention of the required `type`/`attributes` envelope, the mandatory `label`, or the enum-constrained `shown`/`required` placement lists. The nested schema does document its own properties, which prevents a 1, but the description itself contributes zero parameter meaning.

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 and resource ("Creates a new custom field") and immediately flags deprecation, which distinguishes it from the active form-field creation siblings. The trailing "from provided data" adds nothing, but the core purpose is unambiguous.

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?

Explicitly routes the agent away from this tool with "Use form field endpoints instead", which is a real alternative-selection signal rather than implied usage. It does not name the specific sibling (create_form_field) nor say under what legacy conditions this tool would still be correct, so it stops short of a 5.

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