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

Annotations already provide readOnlyHint=false and destructiveHint=true, so the agent knows it is a state-changing operation. The description adds no additional behavioral details about side effects, asynchronous provisioning, or cost implications. The product table is useful for parameter selection but not for behavioral 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 opening sentence repeats 'Create a new instance' from the title, creating redundancy. The large HTML table is information-dense but makes the description verbose. Structure could be improved by front-loading the key purpose and placing the table separately.

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 multi-parameter creation tool with no output schema, the description should explain return values, provisioning status, and cost implications. It only provides product selection details. The lack of usage guidelines and behavioral disclosure leaves significant gaps.

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 schema covers many parameters with descriptions (e.g., period, region, sshKeys), but the description adds significant value by mapping productId values to product names and disk sizes via the table. This is critical because the schema's productId description only mentions the default value. However, the description does not cover other parameters that lack schema context.

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 'Create a new instance for your account with the provided parameters,' which identifies the action and resource. It distinguishes from sibling create tools like createCustomImage or createSnapshot by specifically mentioning 'instance.' However, the title already says this, and the description could be more explicit about provisioning a compute instance.

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?

No guidance is given about when to use this tool versus alternatives like upgradeInstance, reinstallInstance, or patchInstance. There is no mention of prerequisites such as account verification or billing setup.

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