get_cpu_usage

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, establishing safety. The description adds value by specifying the return format (inline bar chart) and the exact data points (per-core and total percentage, core count, frequency), which is behavior beyond 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?

A single, well-structured sentence front-loads the primary purpose ('Returns CPU usage percentage') and then lists additional details. Every phrase is informative and there is no redundancy or extraneous text.

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?

Without an output schema, the description bears responsibility for explaining return values. It covers the key elements: total and per-core usage, core count, frequency, and the bar chart. Minor ambiguities like frequency units and sampling methodology prevent a perfect score, but it is complete for a simple monitoring tool.

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, so the schema is trivially complete (100% coverage). The description does not need to explain parameters, and it instead provides useful output details. Baseline for zero-parameter tools is 4, which is appropriate here.

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 specific verb ('Returns') and identifies the resource ('CPU usage') with detailed scope: total and per-core percentage, core count, frequency, and inline bar chart. This clearly distinguishes it from sibling tools like get_ram_usage and get_gpu_usage.

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 intended use is evident from the description: it provides CPU metrics. While it doesn't explicitly name alternatives or exclusions, the context is clear within the system-monitoring tool family. The lack of explicit when-not-to-use is a minor gap, but the description is sufficient for a simple read-only metric.

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