Update custom field

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

Annotations already indicate this is a mutating, idempotent operation. The description adds the key behavioral detail that only provided fields change, preventing the agent from assuming a full replacement. It does not describe side effects like option handling, but the annotation coverage lowers the burden.

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, focused sentences. The main action is front-loaded and the second sentence clarifies a critical behavioral constraint without wasting words.

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?

The description covers the core action and partial-update behavior, but it omits when-to-use guidance, any mention of required identifier beyond the schema, and return/error behavior. Since this is a mutation tool with 6 parameters and no output schema, slightly more context would be valuable, though it is minimally sufficient.

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 very low (17%), so the description carries some burden. It adds general patch semantics but does not explain individual parameters like options or placeholder. However, the parameter names are mostly self-explanatory and customFieldId is clearly the target identifier.

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 clearly states the action ('Update') and the resource ('a custom field definition'), and the phrase 'Only provided fields change' adds important partial-update semantics. This distinguishes it from sibling tools like ghl_create_custom_field and ghl_delete_custom_field.

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 implies the tool is used when an existing custom field definition needs modification, but it does not explicitly mention alternatives such as create or delete custom field tools, nor does it provide conditions like 'use create for new fields.' The intended usage is mostly inferred from the name and siblings.

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