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

readOnlyHint=true already tells the agent this is a safe read, so the description's only job is to add context — and it does not. It says nothing about whether results are filtered to the caller's own groups, whether an empty list or error results when the client belongs to none, or how the groups are returned.

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 short clause with no padding, so nothing is wasted — but the terseness is under-specification rather than economy. There is no front-loaded verb to establish the operation.

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?

A simple one-parameter tool with no output schema is a low bar, yet the description still leaves the return value undefined (group names? IDs? counts?) and gives no hint that the result is scoped to groups the coach owns or manages. The agent can call it, but cannot predict what comes back.

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% for the single parameter, but the name clientId is self-explanatory and the description confirms the 'client' whose groups are listed. It adds identification but no format hints (ID vs email) or scope constraints, so it only marginally compensates for the missing schema documentation.

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 phrase names the resource (groups) and the scope (a specific client, from the coach's groups), so the agent can infer it is a read of group membership. But it is a noun fragment with no verb — it never says 'list' — and it reads like a restatement of the tool name rather than a statement of what the tool does.

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 guidance on when to use this versus obvious siblings such as list_client_groups, get_group_overview, or list_group_assignments, which appear to return overlapping information. No prerequisites or exclusions are stated, leaving the agent to guess from names alone.

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