list_custom_fields

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

No annotations are provided, so the description carries the full burden. It discloses the return structure in detail (field groups, fields with name, pretty_name, type, options) and explains how to use the results. It does not mention any destructive behavior or authentication, which is acceptable for a read-only list operation.

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 clear sections: purpose, usage, return format, cross-references. It is not overly verbose and front-loads the key information. Minor redundancy (e.g., 'IMPORTANT' and then same info) could be trimmed, but overall efficient.

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 no output schema, the description fully explains the return values and how to interpret them. It covers input, output, and usage context comprehensively. Adequate for a simple tool with one parameter.

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 schema coverage is 100% with the 'entity' parameter already documented via enum and description. The description does not add extra parameter semantics beyond what the schema provides, but the schema itself is sufficient. Baseline 3 is appropriate.

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 'List custom field definitions for an entity type in Propstack.' It uses a specific verb+resource and distinguishes itself from sibling tools by explaining that it discovers fields before reading/writing.

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?

Explicitly says 'Call this tool to discover what custom fields exist before reading or writing custom field values.' It also provides guidance on when to use other tools (search with expand, write with partial_custom_fields), making the usage context very clear.

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