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

readOnlyHint=true already covers the safety profile, so the bar is lower; the description adds value by disclosing that the payload includes searchable ($filter) and editable flags, which hints at how the metadata can be applied. It does not discuss result size or ordering, but for a read-only metadata listing this is adequate.

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?

Two tight sentences: the first front-loads what is returned, the second front-loads why to use it, followed by a compact API reference. No filler or redundancy.

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?

With no output schema, the description carries the burden of describing the return payload, and it does so concretely (names, codes, types, allowed values, flags). Missing only minor operational detail such as whether the list is exhaustive or paginated, which is low risk for a field-definition endpoint.

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 per the rubric the baseline is 4. The description correctly implies no input is required, and nothing about argument semantics is left ambiguous.

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?

States a specific verb and resource ('List the contact and membership field definitions') and enumerates what the definition contains — names, system codes, types, allowed values, searchable, editable. This clearly distinguishes it from sibling list tools such as wildapricot_list_contacts, which returns contact records rather than field metadata.

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?

Gives an explicit reason to call it ('Use it to build filters and field_values'), which tells the agent when this metadata is needed. It stops short of naming an alternative sibling or stating when not to use it, but the purpose-driven guidance is clear.

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