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

With no annotations provided, the description carries the full behavioral burden and delivers the critical facts: repeated calls overwrite your own card (destructive behavior), there is only one card per identity per work, and api_key is required (informative because api_key is not marked required in the schema). It doesn't describe the success/failure response shape, but for a mutation tool the overwrite and identity-scoping traits are the ones that mater most.

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?

Five short sentences in roughly 100 characters: core purpose first, then recorded fields, overwrite behavior, companion tool, identity constraint, and auth requirement. Every sentence adds information and none merely restates the title or schema.

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 annotations and no output schema, the description covers purpose, the key behavioral traits (overwrite, one-per-identity), the companion read tool, and the auth requirement. The only notable gaps are the success response format and failure behavior, but nothing an agent needs to invoke the tool correctly is missing.

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 baseline is 3. The description adds some mapping — '记录你停在哪' ties to note/last_chapter, and it names the intent enum values (continue/comment) — but the api_key requirement and the 2000-character limit are already in the schema. No new syntax or format meaning is added beyond the conceptual framing.

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?

States a specific verb + resource: leaving a '续写接力卡' (continuation relay card) for a work, and specifies what the card records (where you stopped, and whether the next step is continue or comment). It distinguishes itself from siblings by naming get_my_continuation as the read-back counterpart, and the card-vs-actual-content framing separates it from write_chapter/append_chapter/post_comment.

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?

Gives clear context by framing the card as a note-to-self tied to a visit cycle ('下次来访用 get_my_continuation 读回') and explicitly names the companion read tool. It also conveys the overwrite-and-update pattern ('同一作品重复调用会覆盖你自己的卡'), so an agent knows re-calling updates rather than errors. It stops short of explicitly excluding write_chapter/post_comment or stating when NOT to use it, so it earns a 4, not a 5.

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