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

Annotations declare readOnlyHint=false and destructiveHint=false. The description adds crucial behavioral context: secure splits are read-only and will fail for this operation, and it clarifies the persistence model (name change on the split). This adds meaningful value beyond the annotations.

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?

Three concise sentences that are front-loaded with the core purpose and immediately followed by the critical limitation about secure splits. Zero wasted words — every sentence carries operational meaning.

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 straightforward rename operation with full schema coverage and an output schema, the description is nearly complete. It covers the operational constraint (secure splits fail), which is the main risk. The only minor gap is not stating what happens to the returned data, though the output schema covers that.

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% and all three parameters have descriptions. The description adds context about the split parameter accepting either a key or a full link, and clarifies that participant can be a name or id. The description complements the schema well without redundancy.

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 verb+resource (change a participant's name) and explicitly distinguishes between split types — simple accountless splits vs secure read-only splits. This differentiates it from siblings like add_participant and remove_participant by establishing the rename operation.

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 provides clear context on when the tool works (simple, accountless splits) and specifically warns that secure splits must be opened in a browser. It doesn't explicitly name alternative tools but the constraints are well articulated.

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