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

With no annotations, the description carries the behavioral disclosure burden. It does disclose the admin-auth requirement and implies a persistent write by 'Create a role.' However, it does not describe what happens on success, whether duplicate names are rejected, or how the resulting role can be referenced later.

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?

Two sentences, both purposeful: the first defines the resource in plain terms, the second states the key authorization constraint. No filler or repetition of schema details.

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 simple three-parameter create operation with no output schema, this description is largely sufficient: it explains the resource, the authorization requirement, and the core conceptual model. Minor gaps like idempotency and return behavior remain, but they are not critical for selecting or invoking the tool.

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 schema already documents owner_key and scope_expressions, so the description's conceptual definition ('reusable set of scope_expressions') adds some context for those parameters. It also hints that 'name' is the role's identifier, but it does not add concrete constraints like uniqueness or naming rules beyond the schema.

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 clearly names the verb ('Create') and resource ('a role'), and defines what a role is: a named, reusable set of scope_expressions an access_key can be bound to. It does not explicitly contrast it with sibling tools like update_role or delete_role, so it stops short of full sibling differentiation.

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 gives a clear usage condition: an admin owner_key is required, and access_keys can never call this tool. This is explicit context about who is allowed to invoke it, but it does not say when to choose this over alternatives like update_role or list_roles.

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