manage_custom_fields

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

The description adds some behavioral context beyond annotations (which are absent). It explicitly notes that delete is 'destructive', which is useful for safety awareness. However, it lacks details on permissions, rate limits, response formats, or error handling, leaving significant gaps for a mutation tool.

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 front-loaded, stating the core purpose in the first clause. However, the list of actions ('list, create, update, delete') could be integrated more smoothly, and the second sentence is somewhat redundant with the first.

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 complexity (managing fields with destructive operations), no annotations, and no output schema, the description is incomplete. It covers basic actions and a safety warning but lacks details on input/output formats, error cases, or integration with sibling tools, which are needed for effective use.

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?

With 0 parameters and 100% schema description coverage, the baseline is high. The description implies that actions are determined internally (e.g., 'list, create, update, delete'), but since there are no parameters, this doesn't add semantic value beyond what the empty schema already indicates.

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's purpose: managing custom subscriber fields with specific actions (list, create, update, delete). It specifies the resource ('Kit custom subscriber fields') and verbs ('manage'), though it doesn't explicitly differentiate from sibling tools like 'manage_subscribers' or 'manage_tags'.

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 provided on when to use this tool versus alternatives. While the description mentions actions like 'list, create, update, delete', it doesn't specify prerequisites, appropriate contexts, or when to choose other tools like 'manage_subscribers' or 'bulk_operations' for related tasks.

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