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

Annotations already declare the mutation as non-read-only, idempotent, and destructive. The description adds useful behavioral context beyond that by stating the owner-only authorization requirement and explaining what each role can do ('viewer read only' vs 'member read and change the setup'). It does not explicitly warn that a downgrade immediately removes access, but the role definitions convey the effect.

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 a single front-loaded sentence with no filler. Every clause contributes: the action, the resource, the authorization restriction, and the role meanings.

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 role-update mutation with rich annotations and no output schema, the description covers the essential authorization and role semantics. It does not describe response behavior or explicitly state side effects such as immediate permission loss, but it is otherwise sufficient to call the tool 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?

Schema description coverage is low at 33%, so the description should compensate. It meaningfully explains the role enum values and their privileges, which is the main semantic ambiguity; the site parameter already has a rich schema description, and email is a standard required email field.

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 verb and resource: change the role of a person on the site. It also gives the scope ('owner only') and the allowed roles, making it easy to distinguish from invite_team_member or remove_team_member without opening the schema.

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 provides an important prerequisite ('owner only') and explains the two role meanings, but does not explicitly say when to use this instead of invite_team_member or remove_team_member. Usage is implied by 'change the role' rather than stated with alternatives.

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