StartInstances

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

No annotations are provided, so the description carries the full burden. It mentions the tool is for batch operations but doesn't disclose critical behavioral traits such as permissions required, whether it's idempotent (e.g., starting already-running instances), potential costs, rate limits, or error handling. For a mutation tool with zero annotation coverage, this is a significant gap in transparency.

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 description is a single, efficient sentence that front-loads the purpose and provides context. Every part earns its place by explaining the tool's function and typical use cases without unnecessary elaboration, though it could be slightly more structured for clarity.

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?

Given the complexity of a mutation tool (starting instances) with no annotations and no output schema, the description is incomplete. It lacks details on behavioral aspects (e.g., side effects, permissions), output format, or error conditions, which are crucial for safe and effective use. The description does not compensate for the missing structured data.

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%, with both parameters (InstanceIds and RegionId) well-documented in the schema. The description doesn't add any meaningful parameter details beyond what's in the schema, such as format examples or constraints. With high schema coverage, the baseline score of 3 is appropriate as the schema handles the heavy lifting.

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 clearly states the action ('批量启动' - batch start) and resource ('ECS实例' - ECS instances), and specifies it's for managing multiple instances simultaneously. However, it doesn't explicitly differentiate from sibling tools like 'RunInstances' (which creates new instances) or 'RebootInstances' (which restarts running instances), though the context of 'starting' versus 'creating' or 'rebooting' is implied.

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?

The description provides clear usage context with examples ('应用部署和高可用性场景' - application deployment and high-availability scenarios), indicating when this tool is appropriate. It doesn't explicitly state when not to use it or name alternatives like 'RunInstances' for creating instances or 'StopInstances' for stopping them, but the context is sufficient for general guidance.

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