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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, yet the description adds substantial non-obvious context: permissions live only in roles, people carry none of their own, and owners/org-level accounts hold no role and are never restricted by a role change. That owner caveat is exactly the kind of behavioral disclosure an agent cannot derive from annotations.

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?

The core purpose is front-loaded and the FAQ-style examples and owner caveat each earn their place. It runs slightly long with a few overlapping clauses, keeping it just below a 5.

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-parameter, read-only list tool with no output schema and full annotation coverage, the description supplies everything needed: what it returns conceptually, when to call it, how to reuse the output (permission ids for revocation), and the important owner exception.

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 per the rubric. The description correctly adds no parameter detail because there is nothing to parameterize, and schema coverage is 100%.

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 gives a specific verb+resource ('The roles this merchant has defined and exactly what each one is allowed to do') and scopes it further with the concrete questions it answers. It is clearly distinguishable from siblings like hub_get_permissions, hub_create_role, or hub_get_team 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 explicit timing guidance ('Read this before changing anything, and take permission ids from the granted list when revoking'), which is a real when-to-use signal. It stops short of naming the alternative tools (e.g. hub_get_permissions) or stating when NOT to call it, so it does not reach a 5.

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