create_snapshot

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

No annotations are provided, so the description carries the full burden of disclosing side effects and requirements. It only states the action and return value, with no mention of permissions needed, whether the operation is asynchronous, whether the disk must exist, or any impact on the disk. This is insufficient for a mutation tool.

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 well-structured and concise, with a clear purpose sentence, an Args list, and a Returns section. Every part serves a purpose, no redundant text exists, and it is front-loaded with the primary action. It is appropriately sized for the tool's complexity.

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 tool has 5 parameters, no annotations, and no output schema, the description is incomplete. It omits usage guidance, prerequisites, error conditions, and behavioral details like synchronous vs asynchronous execution. The minimal Args/Returns structure does not suffice for an API operation of this complexity.

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 has no descriptions (coverage 0%), but the description includes an Args section that defines each parameter, adding meaning like the zone example ('us-central1-a') and noting description is optional. However, the explanations are minimal and lack constraints, dependencies, or format details, so it only partially compensates for the schema gap.

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 specific action: 'Create a snapshot of a Compute Engine disk.' This identifies the verb, resource, and scope, distinguishing it from sibling tools like list_snapshots or create_backup. The purpose is immediately clear from the first sentence.

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 no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., disk existence), exclusions, or situations where other tools (like create_backup) would be more appropriate. Usage context is only implied by 'Create a snapshot,' but no explicit direction is given.

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