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

Annotations already declare non-readOnly, non-destructive, non-idempotent, so safety is covered. The description adds real behavioral context: what isDefault actually does, that privilege keys are matched whole (REPORTS_VIEW != REPORTS_VIEW_ALL), and that role capabilities are only defaults until read back. It omits what happens on a duplicate key or invalid privilege, which keeps it from a 5.

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?

Purpose is correctly front-loaded, but the middle drags in integration-architecture advice (flag rules, never hard-coding role checks in app code) that is only tangential to invoking this tool. The parameter listing is a single dense sentence and the piece is longer than the operation warrants.

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 6-parameter mutation tool with no output schema and full schema coverage, the description covers purpose, routing, parameter intent, and downstream integration needs. Only failure modes (duplicate key, unknown privilege) are unaddressed.

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 coverage is 100%, so the baseline is 3, but the description still adds value: it characterizes privileges as KEYS and points to list_roles for the valid set, restates key as a stable code reference, and clarifies isDefault's default. It does not add syntax beyond the schema, so not a 5.

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?

Opens with a specific verb+resource ("Create a new access role") and immediately separates itself from update_role and set_default_role, so an agent can route correctly without opening a schema. The scope is unambiguous.

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?

Explicitly names the alternatives and the condition that selects them: use update_role for an existing role, set_default_role to promote an existing one. It also routes the agent to list_roles for privilege keys and get_integration_guide before writing consuming code.

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