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 genuinely useful behavioral context by disclosing that inactive fields are included and that list-type fields carry their selectable items — details an agent could not derive from annotations. It stops short of stating anything about pagination or response size.

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?

One dense sentence plus the HTTP endpoint — front-loaded and waste-free. The raw endpoint (GET /v1/CustomFields) is marginally redundant but small and aids traceability.

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 return-value burden and does so adequately by naming the attributes returned (type, requiredness per service offering, selectable items) and the active/inactive scope. Missing only pagination/shape detail for a potentially long list.

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 nothing for the description to disambiguate; baseline 4 applies. The description correctly implies a no-argument, company-scoped call.

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 resource (the company's custom fields) and enumerates the content returned: type, requiredness per service offering, and selectable items for list fields. It does not explicitly name how it differs from siblings like bilflo_list_custom_field_items or bilflo_get_job_custom_fields, though the 'company-wide, active and inactive' framing hints at the distinction.

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?

No explicit when-to-use or when-not-to-use guidance and no alternatives are named, so an agent must infer that this is the definitions-level lookup versus bilflo_list_custom_field_items (per-field values) or bilflo_get_job_custom_fields (job-scoped). The 'active and inactive' note is the only scoping cue.

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