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

Beyond the annotations (destructiveHint=true), the description adds crucial context: only the owner can perform this action, the owner's own role is protected, and the tool returns the updated member record. This gives the agent a solid understanding of side effects and constraints.

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 concise sentences that are front-loaded with the core purpose and then provide necessary usage details. No wasted words.

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, the description is complete: it specifies the operation, required permissions, constraints, and return value. No output schema exists, but the return behavior is explicitly stated.

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 covers all three parameters with descriptions and an enum. The description adds the relationship to list_members for obtaining memberId/email and clarifies the alternative identification methods. This is helpful context that goes slightly beyond the schema, though the schema itself is already informative.

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 the action ('Change a member's role') with specific role values ('editor, viewer, and billing'), and the resource ('member'). It also differentiates from sibling tools like invite_member and remove_member by focusing solely on role changes, and adds the restriction for the project owner.

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?

It explains how to identify the member ('member ID or email (from list_members)') and notes the exclusion (project owner's role cannot be changed) and the access requirement ('Owner only'). While it doesn't explicitly name alternative tools, the reference to list_members and the context make the usage clear.

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