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

Annotations already declare readOnly=false, idempotent=false, destructive=false, openWorld=true, so the safety profile is covered. The description adds genuinely new context: the required permission scope (servers:reboot), the account/MCP-key prerequisite, and the 'hard' qualifier distinguishing it from a graceful reboot. It stops short of stating downtime or impact on running workloads.

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?

Two short sentences, action front-loaded, with permission and auth requirements tucked into parenthetical/bracket clauses. No wasted words, though the bracketed account note reads as boilerplate rather than tool-specific 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 single-parameter mutation tool with annotations covering the safety profile, the description covers purpose, required permission, and account requirements. It omits any indication of what happens on success (no output schema exists) and whether reboot causes transient unavailability, leaving an agent with a bare minimum picture.

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 a single parameter with 100% schema description coverage, and the schema already documents serverId including its source (gpucloud_list_servers). The description adds no parameter-level detail, so the baseline of 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 scope: 'Hard-reboots a running server'. The verb 'hard-reboot' is unique among siblings (start_server, stop_server, hibernate_server, restore_server), so an agent can route to it without confusion. It does not, however, explicitly contrast itself with those siblings, keeping it just short of 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 phrase 'a running server' implies a precondition (the server must be running), which is implicit usage guidance. There is no explicit when-to-use statement, no naming of alternatives (e.g., stop+start vs reboot), and no exclusion for stopped/hibernated servers.

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