Select an option at a visual novel choice point and record a one-sentence reason for the agent's persona, enabling reasoned branching decisions.
Pick an option at a choice and say why. / 选选项并写理由
| Name | Required | Description | Default |
|---|---|---|---|
| i | No | option number from 1, or "random" | |
| book | No | 书的 slug（见 galbook_books）。服务端设了默认书时可省略 | |
| agent | No | 你的玩家名（1-40 位字母数字/中日文/_-.）。服务端设了默认名时可省略 | |
| reason | No | one sentence: why your persona picks this |
Changes observed during successful MCP inspections.
v1.2.6Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full behavioral burden, and it discloses almost nothing. It does not say that choosing mutates story/save state, whether the action is irreversible, what happens with "random", whether reason is mandatory, or what the caller gets back.
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?
The text is short and front-loaded, which is good, but it is under-specified rather than genuinely concise, and the bilingual duplication doubles length without adding information. Every word does not earn its place given the gaps left open.
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 4-parameter tool with no annotations and no output schema, the agent needs to know the outcome of a choice and its side effects, and none of that is present. All parameters being optional (0 required) also goes unexplained, leaving the caller guessing which fields are truly needed.
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 the schema already explains i (including "random"), book slug, agent name constraints, and the one-sentence reason format. The description adds only the loose expectation of "say why", which duplicates the reason parameter rather than adding new meaning; baseline 3 applies.
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?
"Pick an option at a choice and say why" gives a concrete verb (pick) and a domain-specific resource (an option at a choice), so the intent is inferable. However, it never distinguishes itself from siblings like galbook_click, galbook_next, or galbook_look, which could plausibly also advance or select within the story.
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 guidance on when this tool applies versus galbook_click or galbook_next, nor any mention of prerequisites such as needing a pending choice or a configured book. The only implied condition is circular: use it at a choice.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.