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

The annotations only say readOnly=false, destructive=false, idempotent=false, openWorld=true; the description adds the material behavior an agent actually needs: this spends money, the billing mechanics of the next hour, the card/credits requirement, the required 'servers:start' permission, and the account/MCP-key prerequisite. That is real cost and authorization context beyond structured fields, and it is consistent with the annotations.

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 action and its scope are front-loaded, and the bracketed [SPENDS MONEY] / permission / prerequisite tags are scannable. The billing sentence is dense and heavily parenthesized, which costs a little readability, but every clause carries operational information.

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 costly mutation with no output schema, the description covers cost, payment source, permission, and prerequisites — the essentials. It stops short of saying what happens after a successful start (state transition, whether boot completes asynchronously), which would have made it fully 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?

There is one parameter with 100% schema coverage, and the schema already explains that serverId comes from gpucloud_list_servers. The description adds no further semantics about the id or its format, so the schema is doing all the work — baseline 3.

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 ('Starts a stopped server') and immediately scopes it: only stopped servers, not hibernated ones. It explicitly routes the hibernated case to gpucloud_restore_server, so the agent can distinguish it from sibling power tools (stop, reboot, restore, renew) without opening a 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?

Gives the when ('stopped server'), the when-not plus the exact alternative ('For a hibernated server use gpucloud_restore_server'), and the preconditions for the spend (credits covering the hour, or a saved card with ≥$25 available within caps). Nothing about selecting this tool over its siblings is left to inference.

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