list_custom_fields

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

No annotations are provided, and the description only states 'List all custom fields.' It does not disclose whether the operation is read-only, whether it requires specific permissions, whether results are paginated, or what the response format is. The verb 'List' implies non-destructive behavior, but without explicit detail, the description carries minimal transparency.

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, direct sentence with no unnecessary words. It is front-loaded with the action and resource, making it easy to parse. There is no wasted content, and the length is appropriate for a zero-parameter tool.

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 no-parameter list tool, the description is mostly complete: it conveys the essential action and resource. However, without an output schema, it does not specify what fields are returned or any potential caveats like pagination or filtering. Given the simplicity, the description is adequate but lacks deeper contextual richness.

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 tool has zero parameters, so schema coverage is complete (100%). Per the rubric, the baseline for 0 params is 4, and the description adds no parameter-related meaning but is not required to do so. It does describe the scope ('all custom fields'), which adds a bit of context.

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 identifies the action ('List') and resource ('custom fields'), distinguishing it from sibling tools by resource type. However, it does not differentiate its scope beyond the name, such as whether it returns all fields or only active ones, so it lacks explicit sibling differentiation.

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?

There is no guidance on when to use this tool versus alternatives, no mention of prerequisites, and no exclusions. The agent must infer usage solely from the tool name and context, which is insufficient for a robust selection decision.

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