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

The description states that the operation is read-only and elaborates that members, roles, teams, and SSO are not changeable via MCP, which aligns with the readOnlyHint annotation. It adds context about the tool's non-destructive nature, though it does not mention potential errors or rate limits.

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 concise, using two sentences to convey the tool's purpose, usage guidance, and read-only nature. It is well-structured and front-loaded with the core functionality.

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?

Without an output schema or parameters, the description covers all necessary information: what the tool returns, how to use it vs. alternatives, and its read-only behavior. It is sufficiently complete for an agent to invoke correctly.

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?

There are no parameters, so the schema provides complete coverage by default. The description adds no parameter-specific information, but this is unnecessary given the absence of parameters, earning the baseline score for zero-parameter tools.

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 states that the tool lists custom roles, including permission strings and member counts. It also distinguishes itself from get_custom_role, which retrieves a single role with permissions. This makes the purpose 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?

The description explicitly recommends using this tool to browse custom roles and refers to get_custom_role for individual role details. It also notes that organization context is required, providing clear guidance on when to use this tool.

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