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

Annotations already declare destructive=true and idempotent=true, so the safety bar is partly covered. The description adds genuinely useful behavior beyond them: the change applies only to new stories, existing stories retain their numbers, and value=null reverts to the value's own start (an undo/reset path that contextualizes the destructive hint). Auth/permission requirements are not mentioned.

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 tight sentences with the scope constraint front-loaded and the null behavior and alternative workflow following in priority order. Slightly dense/idiomatic phrasing ('Give one character a different start') but no wasted text.

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 mutation tool with no output schema, the description covers scope, side-effect boundaries, and the null/reset path, and points to sibling tools for the IDs it consumes. Missing only permission/auth context; otherwise an agent has enough to call it 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 coverage is 80% and the schema itself documents value as 'a number, one of the options, a few words, or null to clear'. The description only enriches the null case ('goes back to the value's own start'), adding marginal meaning over the schema. Baseline 3 is appropriate given the schema carries most parameter documentation.

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 a specific action (set a start value) on specific resources (one character, one value) with a clear scope (every NEW story of the world). It implicitly distinguishes itself from set_world_status by narrowing to a single character/value, though it never names that sibling to sharpen the contrast.

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 the operative condition ('every NEW story... stories already going keep their numbers') and routes the agent to a concrete alternative workflow: read the reached number with get_story_status and send it here. It gives clear when-to-use context but no explicit when-not-to-use beyond the new-stories scope.

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