monitor_get_disk_usage

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

Annotations already declare readOnly, idempotent and non-destructive, so the bar is lower. The description nevertheless adds real value by disclosing that mounts raising PermissionError are skipped, meaning results can be a partial partition list — a behavior not visible in any structured field.

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?

Front-loaded with the core purpose in a single clause, and the sections are clearly delimited. The Return Format block is largely redundant given an output schema exists, which costs a little space.

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 zero params, full annotation coverage and an output schema present, the definition covers what an agent needs to call it. The one remaining gap is that the 'usage' field's unit (percent vs bytes) is never stated anywhere.

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?

Zero parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate. The example call correctly reinforces that no arguments are needed.

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+resource: per-partition disk usage, which is clearly distinguishable from siblings like monitor_get_memory_info or monitor_get_cpu_info. It doesn't explicitly contrast with monitor_get_resource_usage or monitor_get_system_status, which may also surface disk figures.

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?

No statement of when to use this versus the other monitor_* tools, and no prerequisites or exclusions. The PermissionError note describes behavior during execution, not when to select the tool, so the agent must infer selection from the name alone.

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