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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered elsewhere. The description adds no behavioral context of its own: no scoping to a workspace, no pagination or filtering behavior, no volume/auth expectations. Nothing contradicts the 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?

The single substantive sentence is duplicated verbatim, which is pure waste, and the content is an endpoint path rather than a front-loaded statement of purpose. The remaining clauses are an operation ID and a pointer to another tool.

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, 0% parameter coverage, and nested-object parameters, the description carries the full burden of explaining how to call this and what comes back — and it does none of that. The deferral to describe_operation for the request schema is the one mitigating element, but an agent gets no information about response shape or filtering here.

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 0% and the two parameters (a free-form `query` object and an empty `params` object) are entirely opaque. The description does not explain what belongs in `query` — filters, field names, pagination — and instead defers with 'describe_operation provides native request schemas'. That pointer is genuinely useful but it is a lookup instruction, not parameter semantics.

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 is only the raw endpoint path 'GET /api/global-settings/custom-field-definitions' repeated verbatim, which restates the tool name and title rather than explaining in plain language what a custom field definition is or what the call returns. It never distinguishes this from the many sibling custom-field endpoints (e.g. get_contacts_custom_fields_definitions, get_leases_by_id_custom_fields_definiti) or clarifies that this one is the global/workspace-level catalog.

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 statement of when to use this tool, when not to, or which sibling to prefer for related custom-field data. The only actionable hint is the pointer to describe_operation for native request schemas, which is a mechanical aid, not usage guidance.

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