rescan_storage

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

Annotations only give the coarse safety profile (readOnly=false, destructive=false, idempotent=false, openWorld=true); the description adds substantially more: a preview/confirm gate, the exact blast_radius payload, an anti-pattern warning against auto-confirming, I/O visibility and duration on busy hosts, and a refusal condition. This is well beyond what structured fields convey.

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 operation class and action, then ordered by importance: purpose, usage, when-not, preview semantics, safety warning, cost/refusal, return shape. No sentence is filler despite the multi-sentence length.

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 output schema, the description compensates by stating the return shape (a dict) and the blast_radius contents, plus refusal conditions and timing expectations. An agent has everything needed to call and gate this tool correctly.

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 coverage is 100%, but the description still adds meaning the schema lacks: it explains what the confirm preview actually returns (blast_radius listing host, adapters, mounted VMFS volumes) and why the agent must not set confirm=True without user review. The only untouched param is the deprecated dry_run alias.

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 (rescan) plus the resources touched (all HBAs and VMFS volumes on an ESXi host) and the goal (discover newly presented LUNs and datastores). The [WRITE] prefix signals the mutation class, and it explicitly differentiates itself from add_iscsi_target/remove_iscsi_target.

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?

Gives explicit when-to-use ('when a storage array presents new LUNs, or after out-of-band SAN changes') and explicit when-not ('Not needed after add_iscsi_target / remove_iscsi_target — those rescan automatically'). It also prescribes workflow gating around confirm=True, leaving nothing to inference.

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