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

Annotations already declare readOnlyHint=false and idempotentHint=false, so the agent knows this mutates state and repeated calls are not guaranteed no-ops. The description adds the role vocabulary but does not say whether the role replaces an existing one, what happens if the subject is not yet a member, or how permissions affect the call. No contradiction with annotations, but the added behavioral context is thin.

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, front-loaded with the action and followed by the endpoint and role set; nothing is padded. The raw path notation is slightly redundant with the tool name but cheap and useful for precision.

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 four-parameter mutation with no output schema, the description covers the action and the role domain but leaves out outcome behavior (what the role change does to the member, error/permission cases). The confirm gate is documented in the schema, so that gap is excused, but the mutation semantics remain under-described.

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 schema's own descriptions are placeholders ("role (required)") and declare no enum. The description supplies the actual permitted role values, which is the single most decision-relevant semantic for this call.

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?

"Set a member's role" states a specific verb and resource, and the endpoint path plus the role vocabulary make the target object unambiguous against siblings like org.put or project.put. It stops short of explicitly contrasting itself with sibling mutation tools, but the resource noun alone is distinctive enough.

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 says what the tool does but never states when to reach for it versus alternatives (e.g., removing a membership, or other .put tools), nor any prerequisites such as existing membership or admin rights. The only usage nuance available — the confirm gate — lives in the schema, not the description.

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