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

Annotations already establish this as a safe read (readOnlyHint=true, destructiveHint=false), but the description adds real context beyond them: the authentication constraint ('Signed-in users only — API keys can't call this') and the fact that result ownership determines which administration tools are usable. That auth disclosure is exactly the kind of behavior an agent needs and cannot get from annotations, though pagination/size behavior is unaddressed.

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 is listed, then the ownership gating rule, then the auth caveat. No filler, no restatement of the title, and each sentence carries distinct 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?

There is no input schema to document and no output schema provided, so the description carries the return-value burden and does so (role per workspace, ownership flag). Combined with the auth restriction and the admin-gating rule, an agent has everything needed to call this correctly.

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 per the rubric the baseline is 4; there is no parameter surface the description could clarify. The prose instead describes the shape of each returned record (role, ownership), which is useful but is not parameter semantics.

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 a precise verb and resource ('List the Higgs Hub workspaces you belong to') and immediately defines the returned fields (your role, ownership), which separates it from the neighboring list_workspace_members and list_access_roles. An agent can identify this tool without opening the 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 clear usage context — this is the entry point for discovering the workspaces you belong to — and explains the downstream consequence ('Only workspaces you own can be administered from here'), pointing at why an agent would call it before invite_member, assign_access_role or disconnect_mailbox. It never explicitly names an alternative sibling tool to route away from, so it stops short of a 5.

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