list-custom-fields

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

With no annotations, the description carries the burden of disclosing behavior. It does clarify a key limitation (definitions vs. values), which is useful. However, it omits other important behavioral aspects such as pagination behavior, filter constraints, and read-only implications, though some are present in schema descriptions.

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 two sentences, front-loading the core purpose in the first sentence and a useful cross-reference in the second. There is no fluff or repetition; every sentence earns its place.

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 list tool with 8 parameters and no output schema, the description provides the essential context: it lists definitions, outlines return fields, and redirects to other tools for values. The schema covers parameter nuances well, and the description is sufficient to guide correct use, though a bit more detail on response format would push it higher.

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 input schema provides detailed descriptions for 88% of parameters, so the baseline is 3. The tool description adds no parameter-specific guidance, but the schema descriptions already cover filter operators, pagination limits, and field selection, so the description does not need to compensate.

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 the firm's custom field definitions and enumerates specific attributes (id, name, field_type, owner type, list options). It distinguishes this tool from sibling list tools by focusing on custom field definitions rather than matters, contacts, or other entities.

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 explicitly instructs how to read custom field VALUES by adding 'custom_fields' to get-matter / get-contact / list-matters, making it clear this tool is for definitions, not values. This guides the agent on when to use this tool versus the alternatives.

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