Retrieve a specific custom field's details from Follow Up Boss CRM by providing its ID. Use this to inspect field configuration or validate field references.
Get a custom field by id. (GET /customFields/{id})
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | ||
| extraQuery | No | Extra raw query parameters not explicitly listed above — e.g. FUB custom field filters like custom.ClosingDate on /people or /deals. Keys and values are sent as-is. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It only says "Get," implying a read, but does not disclose idempotency, error behavior, permissions, or whether the resource could differ from related custom-field tools. It adds no meaningful behavioral context beyond the action itself.
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 a single, efficient sentence with the endpoint appended as a useful reference. No filler or redundant wording; it is front-loaded with the primary action.
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 this simple read operation with a required id and an optional extraQuery parameter, the description covers the core action but lacks any behavior/usage context. It is minimally viable: an agent can infer the basic call, but would still need schema details for extraQuery and would not know about error cases or alternative tools.
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 phrase "by id" clarifies that the id parameter is a resource identifier, which the schema does not describe. However, the extraQuery parameter is left entirely to the schema, and with only 50% schema coverage the description could have done more to explain how to use it or when it might be needed. This is adequate but minimal.
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?
Clear and specific: "Get a custom field by id" states a direct verb and resource, and the endpoint (GET /customFields/{id}) confirms the target. It distinguishes from list_custom_fields by specifying a single id, but does not explicitly contrast with get_deal_custom_field, which is a sibling with a similar name.
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?
No usage guidance is provided. The description only states what the tool does, not when it should be used over alternatives like list_custom_fields or get_deal_custom_field, nor any context about common scenarios or required prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.