Make a variant the main script while preserving the old main in history.
Make a variant the main script. The old main stays in history.
| Name | Required | Description | Default |
|---|---|---|---|
| session | Yes | Session as 'Project/folder', an absolute path, or its id (from get_session). An old path still works after a rename or move. | |
| variant | Yes | Variant id from get_session. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this a non-read, non-destructive, closed-world write. The description usefully goes beyond them by disclosing the fate of the prior state: 'The old main stays in history,' which explains the mechanism behind destructiveHint=false and implies reversibility. It does not mention auth/permission requirements, keeping it short of a 5.
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 core action front-loaded and the consequential side effect stated immediately after. Appropriately sized for the operation.
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 two-parameter mutation with no output schema, the description covers what happens to both the promoted variant and the displaced main, which is the key contextual fact. It stops short of noting any side effects on dependent posts/scripts, which would round it out.
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 both parameters ('session' with its id/path/rename handling, and 'variant') are fully documented in the schema. The description adds no parameter meaning beyond that, making 3 the correct baseline.
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 ('Make... the main script') and resource ('a variant'), so the operation is unambiguous. However, it does not differentiate itself from related siblings such as update_variant or restore_script_version, which an agent might plausibly confuse with promoting a variant.
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?
There is no explicit when-to-use or when-not-to-use guidance, and no alternative is named despite close siblings (update_variant, restore_script_version, use_post_variant). The agent must infer the routing from the tool name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.