open_model

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

With no annotations, the description must disclose behavior, and it does: it warns that large model loading takes time, advises waiting several seconds before verifying with list_instances, and notes that calling is unnecessary if the model is already online. It stops short of saying whether a redundant call errors, blocks, or is idempotent, and doesn't state the dependency on the WebServer being started first.

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 short sentences, action first, then the latency caveat, then the precondition for skipping. No redundant restatement of the title or name, and each sentence carries distinct information.

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 one-parameter start operation with no output schema, the description covers the action, the latency behavior, the verification step, and the redundant-call case. The main omission is the precondition that the WebServer itself must be running (via start_webserver), which an agent must infer from siblings.

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 100% and the single 'model' parameter already documents its purpose and points to list_models for discovery. The description adds only the general notion of a model instance, so it does not meaningfully extend parameter meaning beyond the schema — 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?

The description names a specific verb and resource combination ('在 WebServer 上启动（打开）一个模型实例（createinstance）') and maps it to the underlying createinstance operation, so the agent knows exactly what action is performed. It is clearly distinguishable from siblings list_models, list_instances, and start_webserver.

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 explicitly states when to call (to bring a model online), when not to call ('若模型已在线则无需调用'), and points to list_instances as the verification tool after starting. The schema additionally routes the agent to list_models for the model name. This is close to complete routing guidance.

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