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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is covered. The description adds a real behavioral fact beyond them: the membership precondition that causes failure. It stops short of documenting who is authorized to change roles or whether demoting the last OWNER is blocked.

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 short sentences, zero waste, with the operation and its role values front-loaded and the guardrail/alternative in the second sentence.

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 3-parameter mutation with full schema coverage and annotations carrying the destructive/idempotent profile, the description covers what an agent needs to call it correctly. Authorization requirements are the only notable omission, and there is no output schema to explain.

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% — projectId, member (UUID or email) and the role enum are all documented in the schema. The description only restates the enum values already present there, adding no new semantics; baseline 3 applies.

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?

States a specific verb and resource ('Change an existing project member's role') and enumerates the valid role values inline. It is immediately distinguishable from sibling membership tools such as add_project_member and remove_project_member.

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 failure precondition ('Fails if the person has not been added to the project') and routes the agent to the correct alternative, stride.add_project_member, for that case. This is exactly the when/when-not/alternative structure the dimension rewards.

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