zernio_list_custom_fields

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

With no annotations provided, the description carries full burden. It states 'List all custom contact fields' but does not disclose behavior such as whether the list is paginated, sorted, or limited. No mention of read-only nature, rate limits, or output structure. The minimal description fails to inform the agent about important behavioral traits.

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?

One-sentence description that is front-loaded with the verb 'List'. No filler words. Efficiently conveys the action and resource.

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?

Given the tool's simplicity (0 params, no output schema), the description is adequate but not fully complete. It says what the tool does but omits what the output contains (e.g., field names, types, IDs). In the absence of an output schema, the description could provide more detail for agent decision-making.

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?

Input schema has 0 parameters with 100% coverage. The baseline for no parameters is 3. The description does not add parameter information, but none is needed. It does not conflict with schema.

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 specific verb 'List' and resource 'custom contact fields' with scope 'all' and 'in your Zernio account'. It clearly distinguishes from sibling tools like zernio_create_custom_field or zernio_list_contact_tags by naming the exact resource type.

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 on when to use this tool versus alternatives. The description merely states the function; it does not mention prerequisites, when not to use it, or suggest other tools for related tasks like creating or updating custom fields.

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