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

Beyond the annotations, the description discloses rich behavioral traits: reset/rewind increment epoch, fence old grants, preserve history, and do not reset external agents, databases, or provider state. It also clarifies extend semantics, clock mutation risk, destroy semantics, operation-key recovery, and that no grant/credential creation is exposed.

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 front-loaded with the core purpose and action list, then layers in constraints. It is dense and information-rich, though the long compound sentences could be easier to scan; nearly every clause carries useful guidance.

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 complex control tool with rich annotations, a nested action-based schema, and no output schema, the description covers critical behavioral and usage details. It does not describe return values or response structure, which is a minor gap given the absence of an output schema.

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 low description coverage, so the description carries the burden and adds meaningful semantics for actions, snapshotId in reset/rewind, expectedExpiresAt/expiresAt in extend, and operationKey recovery. It does not cover every nested field (e.g., projectId, environmentId, instanceId, epoch) in detail, but the action-specific mapping is strong.

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 states a specific verb and resource: controlling an exact manual service instance/epoch. It enumerates the supported actions (snapshot, reset, rewind, clock, pause, resume, extend, destroy), making the tool's scope immediately clear and distinguishable from related service tools.

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 gives clear usage context and important exclusions: reset/rewind restore modeled state only, extend does not resume compute, destroy is not record deletion, and the run-owned lifecycle rejects this path. It does not explicitly name alternative sibling tools, but the constraints are strong enough to guide selection.

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