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

Annotations already cover readOnly, idempotent and non-destructive, so the bar is lower; the description still adds real behavioral context by declaring the data-isolation boundary ('never cross into another workspace') and explaining what approval_required means operationally. It does not mention result volume, ordering, or pagination, but the presence of an output schema covers return shape.

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?

Three dense sentences with no filler, and the sibling-routing rule is stated up front in the final sentence position. Slight weakness: it leads with a glossary definition of 'workspace' rather than front-loading what the call returns, which delays the actionable information.

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?

For a zero-param, read-only, idempotent list tool with full annotations and an output schema, the description supplies the domain vocabulary and the routing to get_structure that an agent needs. It stops short of stating scope explicitly (e.g. all workspaces the caller can access), but nothing essential is missing.

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?

Zero parameters, so the baseline is 4. The description goes slightly beyond by explaining the semantics of a response field (approval_required) that drives the request_approval workflow, though the output schema already documents return fields.

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 never states the action in a verb+object sentence, but it does define the resource precisely ('A workspace is what the app calls a client ... or a brand') and implies the listing scope by contrasting with get_structure. Sibling differentiation against get_structure is explicit.

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?

It gives a concrete routing rule: use get_structure when you need every workspace with its channels and groups in one call, implying this tool is for the lighter workspace-level listing. It also explains that approval_required implies the request_approval flow. No explicit when-not, but the alternative is named clearly.

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