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

Annotations already declare readOnly, idempotent, non-destructive behavior, so safety is covered. The description adds two genuinely new facts beyond annotations: the returned fields and that the call is free (no billing cost). It says nothing about pagination or result size limits despite a limit parameter, so it stays at an adequate 3.

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?

A single front-loaded sentence with no filler; the returned fields come first and the cost note trails. It reads as a fragment rather than a complete sentence, which is efficient but slightly terse.

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?

There is no output schema, so naming the returned fields (id, name, description) is valuable and partly compensates. But for a listing tool with a capped integer limit and a free-text query, the absence of any pagination or filter semantics leaves a real gap 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 0%, so both parameters (limit with a 1-200 range, query with maxLength 100) are named in the schema without meaning attached. The description does not mention pagination, page size, or that query is a search filter, so it fails to compensate for the coverage gap.

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 the resource (directory groups) and enumerates what each record contains (id, name, description), which distinguishes it from directory_list_users and directory_set_groups. It never explicitly says "list/return", relying on the title for the verb, so it falls short of a full 5.

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 indication of when to call this versus directory_get_user (which likely also surfaces group membership) or directory_set_groups for assignment. Only implied usage from the resource name; no prerequisites, no exclusions.

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