addInstance

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

The description discloses important behavioral traits: it is an upsert (returns existing instance if already exists), and it only supports Aliyun instances. Annotations indicate it is not read-only and not destructive, which aligns with the description. No contradictions.

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 concise (two sentences) and front-loaded with the primary action. Every sentence provides valuable information without redundancy.

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?

The description covers all necessary aspects for an add tool: behavior (upsert), required parameters, parameter alternatives, and constraints. With no output schema, it adequately explains the return behavior. The six parameters are all addressed.

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?

The description adds meaning beyond the schema by explaining the combinatorial requirement ('Either instance_resource_id or host and port must be provided') and the optionality of region. Schema coverage is 100%, but the description clarifies usage constraints.

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 'Add an instance to DMS' and specifies required fields, supported cloud (Aliyun only), and alternative parameter combinations. It distinguishes from siblings like getInstance and listInstances by focusing on creation/upsert.

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 context on when to use: for adding Aliyun instances, with required username/password, and two mutually exclusive parameter sets. It does not explicitly mention when not to use or name alternatives, but the context is sufficient for an agent to infer.

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