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

Annotations only supply readOnlyHint and a title, so the description carries the real burden and does: workspace-level configuration scope, that the list can legitimately be empty, that Person fields omit plain-email options, and that isForTesters=false fields have absent question/description. Those are non-obvious behavioral traits an agent could not infer from the schema or annotations.

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?

Purpose is front-loaded in the first clause and each subsequent sentence carries distinct information (type enumeration, Person-option caveat, isForTesters semantics, empty-list meaning). The sentences are long and clause-dense, which slightly hurts scanability, but there is no 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?

There is no output schema, so the description must explain the return shape, and it does thoroughly: id, type with its full enum, choices for choice fields, Person member options with an exclusion, the isForTesters flag and its consequence, and the empty-list case. Nothing an agent needs to interpret the response is missing.

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 there is no parameter meaning for the description to add; this hits the baseline for a parameterless tool. The descriptive detail it does provide is about return values rather than inputs.

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?

Opening clause gives a specific verb and resource ('List the workspace's custom profile fields') and immediately grounds it in the domain ('the questions testers answer about themselves during onboarding when a beta project has customFieldsRequired'). It also distinguishes itself from the related sibling by explaining that field ids match fieldId on getBetaTesters rows, so an agent can tell which tool answers which question.

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 states the trigger for calling it ('use this to read what an answer means' after seeing customFields entries on getBetaTesters rows) and what an empty result implies. It lacks an explicit when-not or a named alternative to prefer in edge cases, which keeps it just short of a 5.

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