List snapshots

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

The description frames this as a read-only listing that returns billing policy and a usage summary, but annotations declare readOnlyHint=false and destructiveHint=true. Those signals directly conflict, so an agent cannot tell whether calling this is safe or mutating. Per the rubric this mismatch is an annotation contradiction.

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?

Three sentences, each carrying distinct load: purpose/scope, sibling routing, and permission requirement. The core purpose is front-loaded and there is no filler.

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?

With no output schema, the description usefully previews what comes back (billing policy, usage summary), which is exactly the kind of detail an agent needs here. It omits any pagination or ordering behavior, and the safety profile it implies conflicts with the annotations, keeping it short of complete.

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% and the single orderNo parameter is fully documented with pattern, length, and examples. The description adds only the service-type context, which does not meaningfully extend the schema, so the 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?

States a specific verb and resource ('List disk snapshots') scoped to a specific product line (Cloud VPS KVM/VDS), and explicitly names the sibling it is not for Firecracker hosts. An agent can distinguish it from list_firecracker_snapshots without opening either schema.

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?

Names the alternative tool (list_firecracker_snapshots) together with the condition that selects it, and adds a prerequisite ('Requires services:read when called with an API key'). Routing and authorization context are both explicit.

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