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

Annotations already establish readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is clear. The description adds which fields are returned but does not disclose pagination behavior or other edge cases. With annotations covering the safety profile, a 3 is appropriate.

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 sentence that efficiently conveys scope and output fields without unnecessary words. It is well-structured and front-loaded.

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 tool is a straightforward list operation with pagination parameters already described in the schema, and an output schema is present. The description covers the essential purpose and required input, but it does not mention pagination behavior; however, that is adequately covered by the schema and output schema. Thus it is complete enough for the complexity, scoring a 4.

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%, with descriptions for project, pageSize, and pageToken. The description only reiterates the project requirement redundantly and does not add extra meaning to the parameters. 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 clearly states the action (Lists snapshots) and the resource (in a project), and it enumerates the specific fields returned, distinguishing it from sibling list tools like list_disks or list_images. It uses a specific verb and resource, so it scores a 5.

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 implies usage when snapshot listing is needed, and it mentions the required project input. However, it does not explicitly state alternatives or exclusion criteria, though the context is clear from the sibling tools and name. The context is clear and no exclusions are stated, so a 4 is appropriate.

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