Contract Testing: Admin Set User Roles

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

The description discloses that the operation replaces all roles, which is key behavioral context beyond the annotations. Annotations already indicate idempotent, non-read-only, and non-destructive, so the description adds moderate value but does not discuss side effects, permissions, or response behavior.

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 key behavioral information is front-loaded in the first sentence. The parameter list is redundant with the schema, which prevents a perfect score, but the overall description is short, scannable, and not bloated.

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 two-parameter admin operation with clear schema coverage and annotations, the description provides enough information to understand the operation. It lacks return-value details, but no output schema exists and the behavioral scope is straightforward.

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?

Schema description coverage is 100%, and the description repeats the parameter information almost verbatim. It adds no new semantic detail beyond what the schema already provides, so the baseline of 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 states a specific action ('Replace all roles assigned to a user') and clearly identifies the resource (user roles) and scope (admin). It distinguishes this tool from siblings like admin_add_role_to_user and admin_remove_role_from_user by emphasizing 'replace all' semantics.

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 phrase 'Replace all roles assigned to a user' conveys the primary use case and differentiates it from incremental role modification tools. However, it does not explicitly mention when not to use it or name alternatives, so it falls short of fully explicit routing.

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