disk_usage

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

No annotations are provided, so the description carries the burden. Referencing "df -h" usefully signals a read-only snapshot with human-readable output, but it never states that the operation is non-destructive, what permissions it needs, or how the default-host fallback behaves. Adds some behavioral context but leaves real gaps.

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 front-loaded sentence with zero filler; the scope qualifier ("for a host") is placed where it matters. Nothing could be trimmed without losing information.

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?

For a one-optional-parameter read-only tool with no output schema, the definition is nearly sufficient; the df -h reference hints at the return shape. It would be fully complete with an explicit read-only/permission note.

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 single host parameter has 100% schema description coverage, including the "omit for the default host" default behavior, so the schema does the heavy lifting. The description only echoes "for a host" and adds no syntax or format detail beyond it; baseline 3 applies.

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 ("Show") and resource ("mounted filesystem usage") scoped to "a host", which is enough to distinguish it from diagnostic siblings like system_info or listening_ports. It does not explicitly name a sibling it is not, so it stops short of a 5.

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?

Usage is implied by the self-evident purpose, but there is no explicit when-to-use, when-not-to-use, or named alternative among the many ops siblings. An agent can infer the use case, but the definition provides no routing guidance.

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