Get Single Custom Field

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds value by stating 'Read-only — it changes nothing in Procore' and describing failure modes (401, 403, 404) and the defaulting behavior of company_id. This exceeds the annotation baseline without contradicting it.

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 well-structured with a clear lead sentence, then usage context, error handling, and endpoint details. Every sentence contributes value, and it is front-loaded with the primary action. It is slightly longer than necessary but remains focused and organized.

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 single-resource GET with two well-documented parameters and strong annotations, the description is complete. It covers what it does, when to use it, prerequisite resolution, return type, error semantics, and the API endpoint. No output schema exists, but the description adequately states the return is a single JSON object.

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 100%, so baseline is 3. The description adds meaningful context beyond the schema: company_id defaults to the procore_set_config value when omitted, and field_id must identify an existing parent record resolved via the list tool. This enhances the basic path parameter descriptions.

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 specific verb and resource: 'Retrieves a single Custom Field by its ID.' It clearly distinguishes itself from list tools by stating 'Use this when you already know which custom field you want and need its full field set.' This differentiates it from sibling tools like get_all_custom_fields or list_custom_fields.

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?

Provides explicit context on when to use: 'when you already know which custom field you want.' It also instructs the agent to resolve field_id with the matching list tool first, which is a clear prerequisite. However, it does not name the specific list tool or explicitly state when not to use this tool, so it falls 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.