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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent mutation; the description adds the authorization constraint (owner/admin only), which the annotations do not convey. It stops short of explaining partial-vs-full update semantics, which matters given idempotentHint=false.

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 tight sentences with the trigger condition front-loaded and the permission constraint second. Slightly clipped grammar ('When the human wants to...' as an opening fragment) but no wasted content.

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?

An output schema exists so return values need no explanation, and the schema fully covers the four parameters. The description supplies the trigger and the permission gate; the only unaddressed item is partial-update semantics for a non-idempotent mutation.

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%, so each parameter is already documented with meaning and allowed values. The description's enumeration of name/description/visibility merely restates the schema fields without adding format or constraint details, matching the baseline for fully documented parameters.

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 names the resource (circle) and the specific mutable fields (name, description, visibility), so the agent knows exactly what operation this performs. It does not, however, explicitly distinguish itself from nearby siblings such as circles.archive or circles.create, leaving that separation to be inferred.

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 states a clear triggering condition ('When the human wants to rename a circle or change its description or visibility') and a hard prerequisite ('Only circle owners and admins can update'). There is no explicit when-not guidance or named alternative for related operations like archiving.

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