get_io_stats

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It clearly states the operation is read-only, identifies the underlying command (iostat -xd 1 1), and warns about the prerequisite installation. It does not mention execution delay or permission needs, but enough behavioral context is given to set safe expectations.

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?

Three short, purposeful sentences. The first states the result, the second covers the behavior and prerequisite, and the third routes to the appropriate sibling. Every sentence earns its place and important details are front-loaded.

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?

With no parameters, an existing output schema, and a clear read-only behavior declaration, the description covers all relevant operational concerns. It also mentions the required external dependency and points to the correct sibling for cumulative counters, making it effectively complete for its stated purpose.

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 input schema is empty, so the baseline is 4. The description adds useful context by enumerating the metrics returned, which helps the agent understand what kind of statistics it will receive even though no parameters need explanation.

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 begins with a specific verb and resource ('Returns per-device extended I/O statistics') and enumerates the exact metrics covered: throughput, IOPS, latency, queue depth, and utilization. It also distinguishes itself from get_disk_io_metrics by clarifying that it provides extended statistics rather than cumulative counters.

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?

Explicitly states the intended use case ('Use for storage performance analysis') and names the alternative tool for a different need ('get_disk_io_metrics for cumulative counters'). This is exactly the when-to-use and when-not-to-use guidance an agent needs.

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