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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the description's value is in the semantics it adds: which entry is the implicit default when `workspaceId` is omitted, and that archived workspaces are excluded from results. It does not mention pagination or ordering, which are the only remaining behavioral gaps.

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 sentences, front-loaded with what the tool returns, followed by the default-selection rule and the call-to-action. Every sentence removes a concrete ambiguity; nothing is padding.

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 burden of describing the return shape and does so precisely (id, name, site URL, role, and the 'current' marker). It also covers the one exclusion rule an agent needs, leaving nothing essential to inference.

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 the baseline is 4. The description does add meaning about `workspaceId` — that omitting it falls back to the 'current' entry — though that parameter belongs to sibling tools rather than this one, so it stops short of a 5.

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 states a specific verb and resource ('The workspaces this account can open') and immediately enumerates the returned fields (id, name, site URL, caller's role), which distinguishes it from every sibling list_* tool. An agent knows exactly what this tool yields without opening a schema.

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 an explicit trigger ('Read it first when the person works on more than one site') and an explicit follow-up action ('pass the id of the site they mean as `workspaceId` to every other tool'). That is genuine when-to-use guidance plus routing to downstream tools, not just context.

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