Retrieve a deal's custom field by its ID from Follow Up Boss to access deal-specific data for reporting or automation.
Get a deals custom field by ID. (GET /dealCustomFields/{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?
With no annotations, the description carries the disclosure burden. It reveals the HTTP method (GET) and that the operation is a read, but it says nothing about permissions, error behavior, or response format. The endpoint and 'by ID' provide minimal behavioral context without fully disclosing behavior.
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 sentence plus the endpoint, with no filler or duplicated information. Important scoping information (by ID) is front-loaded, and the endpoint adds precision without bloating the text.
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 simple 2-parameter GET tool, the description is minimally sufficient, but there is no output schema and the description does not state what the response contains or any error/edge-case behavior. It also lacks the sibling differentiation needed to make context fully 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 coverage is 50%: extraQuery is documented in the schema, while id is not. The description's 'by ID' adds a small amount of meaning by indicating the id parameter is the target custom field's identifier, but it does not compensate for the missing id docs or explain how extraQuery relates to the operation.
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 uses a clear verb ('Get') and a specific resource ('a deals custom field'), and the endpoint path clarifies it targets a single custom field by ID. It doesn't explicitly distinguish itself from sibling get_custom_field or list_deal_custom_fields, so it isn't a 5, but there is no ambiguity about the operation's core purpose.
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 guidance is given about when to use this tool versus either get_custom_field or list_deal_custom_fields, nor any prerequisites or context. The only implied usage is retrieving one custom field if the caller already has an ID.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.