list_contact_fields

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

With no annotations, the description carries the full burden of behavioral disclosure. It transparently states that it returns complete schema including custom fields, types, and modifiers, implying a read-only operation. However, it does not discuss permissions, potential response sizes, or any other side effects, though for a simple listing tool these omissions are not critical.

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 concise and well-structured, with two sentences that front-load the core action and then add valuable specifics. Every word contributes to understanding, with no redundancy or filler.

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 low complexity (no parameters) and the presence of an output schema, the description is complete. It clearly states what is returned and covers the metadata content, leaving no significant gaps for the agent to infer.

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 takes zero parameters, so schema coverage is trivially 100%. The description does not need to explain any parameters, and the baseline score of 4 for zero-parameter tools is appropriate. No additional parameter context is required.

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 states the tool lists contact field metadata, specifically enumerating tabs, groups, and fields. This precise verb-resource pairing distinguishes it from sibling tools like list_contacts or get_contact, and the additional detail about custom fields and types reinforces its unique 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?

The description implies usage for retrieving the complete schema of contact fields, which is useful for understanding available fields before working with contacts. However, it does not explicitly mention when to use this tool versus alternatives such as create_contact_field or list_contacts, nor does it state any exclusions or prerequisites.

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