Create custom field

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is partly covered; the description meaningfully adds that it changes account state, mandates confirm=true, and requires the OAuth scope custom_fields:write. That auth-scope detail is real behavioral value beyond the annotations.

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?

Three short sentences with zero filler, and the confirm/auth requirements are front-loaded. The only minor waste is the first sentence restating the tool name.

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 destructive 7-parameter mutation with a nested payload and no output schema, the description covers the critical safety (confirm=true), state-change, and OAuth-scope facts. The payload-vs-payload_file-vs-flags distinction is left entirely to the schema, but that is documented there, keeping this largely 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 description coverage is 86%, so the schema already documents nearly all parameters including the confirm semantics and the payload/payload_file relationship. The description's mention of confirm adds only slight emphasis over what the schema states, so baseline 3 is appropriate.

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 opening sentence 'Create custom field' is a clear verb+resource, but it essentially restates the tool name/title and adds no differentiation from siblings like create_publication_field or create_tier. An agent knows it creates a custom field but gets nothing to distinguish it from adjacent create tools.

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?

The description gives a conditional tied to the confirm flag ('for the user-requested action') but never states when to use this tool versus the other create_* siblings, nor any prerequisites beyond the auth scope. No explicit when/when-not guidance is present.

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