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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint), so the bar is lower, and the description still adds real behavior: per-Location labelled output, unreachable Locations reported as skipped, and the blank-location default resolution rule. It omits anything about volume, paging, or error shape, keeping it from a 5.

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 purpose is front-loaded in one line, with parameter detail following in a scoped block; every sentence about location adds information. It runs slightly long for two parameters and the closing note about IDs belonging to one Location is only loosely related to the tool's action.

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 an output schema present, the description needn't explain return values, and it covers the tricky multi-location resolution logic thoroughly. The one meaningful hole is the required `tenant_id` argument, whose meaning and source (e.g., from list_tenants) are never stated.

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 coverage is 0%, so the description must carry both parameters; it does an excellent job on `location` (list syntax, "all" sentinel, blank fallback). However `tenant_id` — the sole required parameter — is never explained beyond its title, so half the surface remains undocumented, which caps this at a middling score.

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 opens with a specific verb and resource: 'List all UDF values for a tenant,' which tells an agent exactly what it retrieves. It does not explicitly contrast itself with close siblings like get_property_udfs, get_unit_udfs, or get_marketing_udfs, so the agent must infer 'tenant' scope is the differentiator.

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?

Usage guidance is strong for the location parameter (comma-separated list, "all", blank default, cross-references list_locations) but says nothing about when to choose this tool over the property/unit/marketing UDF siblings. Selection between siblings is left to inference from the word 'tenant'.

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