VPS what changed

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

With no annotations provided, the description carries the full burden and does so admirably. It discloses stateful behavior (first call creates baseline, server restart resets history), explicitly states no mutation, shell, SSH, network, or secrets, and even mentions the BASELINE_CREATED signal. This is outstanding transparency.

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?

Every sentence earns its place: the purpose is front-loaded, the scope is clarified, exclusions are explicit, and constraints are listed compactly. No filler or redundancy.

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?

Given the tool's simplicity (0 params, output schema present), the description covers everything needed for correct invocation: what it does, how state is managed, what it does not cover, and input constraints. There are no meaningful gaps.

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 tool has zero parameters and the schema coverage is effectively 100%. The description reinforces the contract by stating 'Input must be exactly {}', which aligns with the schema. Per the baseline for 0-param tools, a 4 is appropriate.

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 opens with a specific question, 'What changed since the previous observation made by this MCP process?', and then details exactly what is compared (uptime, CPU count, load, memory). It explicitly excludes deployment, file, service, and container history, which distinguishes it from sibling tools like engineering.deploy.status and engineering.docker.health.

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 clearly states the session/process scoped behavior and the baseline-creation pattern, giving the agent a concrete idea of when to use it. It provides exclusions ('does NOT provide deployment, file, service or container history') but does not name alternative tools explicitly, stopping just short of full routing guidance.

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