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

Annotations already declare this is non-read-only, idempotent, and destructive. The description adds important behavioral context beyond that: the change affects only future stories, existing stories keep their numbers, and null restores the value's own start. It does not describe permissions or failure behavior.

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 no wasted wording. Scope is front-loaded, the null behavior follows, and the copy workflow comes last as a useful operational hint.

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 five-parameter mutation with no output schema, the description covers the critical scope, reset behavior, and copy workflow. It leaves minor gaps like the optional slug's purpose, but annotations cover safety traits and the schema covers most parameters.

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 high at 80%, so most parameter meaning is already documented. The description adds useful semantics for the critical value parameter: null clears back to the value's own start, and a story-reached number can be copied by reading get_story_status. It does not explain slug or all parameter interactions.

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 action and scope: setting one character's start for one value, applying only to every NEW story while existing stories keep their numbers. This distinguishes it from status-reading siblings and from set_world_status less explicitly, but the core operation is clear.

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 gives a concrete usage scenario: to copy a number a story reached, read it with get_story_status and send it here. It also states that null resets to the value's own start. It stops short of explicitly saying when to use this instead of set_world_status.

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