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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds useful context by naming the metrics returned, but does not disclose aggregation behavior, output format, or rate-limit considerations beyond what the period schema field already implies.

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 a single efficient sentence with no wasted words. It is front-loaded with the action and metric scope, though it could be slightly richer without becoming verbose.

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?

The tool is simple, annotations cover safety, and the schema fully documents both parameters. However, with no output schema, the description does not indicate what the returned metrics look like or how they are structured, leaving a small completeness gap for an agent preparing to use the data.

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%, so the id and period parameters are already fully documented in the input schema, including enum values and default behavior. The description only restates that metrics are fetched over a period, adding no syntax or format details beyond the schema.

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 uses a clear verb (Fetch) and names the exact resource and metric domains (CPU, memory, disk, load) for a specific server. It distinguishes itself from generic server metadata tools by focusing on metrics, though it does not explicitly name the sibling tools it differs from.

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?

It states that metrics are fetched for a period, implying historical monitoring usage, but gives no explicit guidance on when to choose this tool over alternatives such as vs_servers_get or vs_monitors_metrics_bulk. No exclusions or prerequisites are mentioned.

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