assign_role_to_subject

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

No annotations are provided, so the description must cover behavioral traits. It explains the side effect: 'The subject inherits all policies assigned to the role.' It does not mention prerequisites (e.g., existence of role/subject) or error conditions, but for a simple mutation, the key behavioral aspect is clear. Good, but could be more thorough.

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 description is two sentences with no wasted words. The first sentence states the action, the second provides context. It is front-loaded and efficient.

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?

Given the tool's simplicity (2 parameters, no output schema), the description covers the purpose, usage guidelines, and basic behavioral transparency. It does not address idempotency or error states, but the core functionality is well-explained. Slightly better than minimum viable.

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 input schema already provides good descriptions for both parameters ('Role UUID', 'Subject UUID') with 100% coverage. The description does not add new semantics beyond the schema; it simply reinforces that the tool assigns a role to a subject. Baseline 3 is appropriate.

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 uses specific verbs ('Give a subject a role') and clearly states the resource and action. It mentions inheritance of policies, which distinguishes it from siblings like 'assign_policy' and 'unassign_role_from_subject'.

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?

The description explicitly states when to use this tool: 'Use this to build RBAC: create a role, assign policies to it, then assign the role to subjects.' This provides a workflow context and implies not to use it before role/policy creation.

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