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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds that this is a definition/metadata listing (not custom field values) and cites the GET endpoint, which is genuinely useful context. It does not mention pagination behavior, whether archived/deleted definitions appear, or how fresh the data is.

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 short sentences, front-loaded with the meaning of the resource; nothing is padded. The trailing 'GET /custom-field-definitions' is slightly redundant for an agent but is a legitimate grounding hint.

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?

This is a zero-required-parameter read tool with full schema coverage and annotations that already carry the safety profile, so the description need not explain return values. What it does provide — that the payload is field definitions with meaning and type across person/job/location scopes — is sufficient for correct invocation.

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?

Schema description coverage is 100% — page and limit are fully documented in the input schema. The description adds nothing about parameter semantics, so the baseline of 3 applies.

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 names the specific resource — custom field definitions — and explains what the resource is ('what each field on a person, job or location means and its type'). That distinguishes metadata/definitions from the list-style siblings such as intellihr_list_people or intellihr_list_reference_data, though it doesn't explicitly name a sibling to contrast with.

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?

There is no when-to-use guidance and no excluded alternatives — nothing says to call this before reading or writing person data, or how it relates to other list tools. The parenthetical hints at a discovery use case but the agent must infer it.

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