storage_iscsi_add_target

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

The description contradicts the annotations: it claims 'Idempotent: a duplicate address:port returns "already configured" without changes,' but the annotation idempotentHint is false. This is a direct contradiction, so the score is 1 per the rubric. The description otherwise adds useful behavioral context (automatic rescan, audit logging) but the contradiction is disqualifying.

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?

The description is cleanly structured: first paragraph states purpose and behavior, followed by prerequisite, idempotency, rescan note, audit logging, and return type, then an Args list. It is a bit lengthy but every sentence adds value. No waste, though it could be slightly more compact.

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 tool with 5 parameters and an output schema, the description is comprehensive. It covers prerequisites, idempotency, side effects (automatic rescan), logging behavior, and return type. The output schema likely covers the return structure, so not describing it in detail is acceptable. No major gaps remain.

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 description coverage is 0%, but the description provides detailed semantics for all 5 parameters in the Args section. It explains host_name as 'ESXi host name as shown in vCenter inventory,' address as 'IPv4/IPv6 literal; hostnames are rejected,' port range, dry_run behavior, and target as optional. This fully compensates for the schema's lack of descriptions.

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 clearly states the action: 'Add an iSCSI send (dynamic discovery) target to an ESXi host's software iSCSI adapter, then automatically rescan all HBAs and VMFS volumes to discover new LUNs.' This uses a specific verb and resource, and the phrase 'No separate storage_rescan call is needed afterwards' distinguishes it from sibling tools like storage_rescan and storage_iscsi_remove_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?

Explicitly states the prerequisite: 'software iSCSI must be enabled first (storage_iscsi_enable); otherwise returns an error with guidance.' It also explicitly notes that no separate storage_rescan call is needed, naming the alternative tool. This gives clear when-to-use and when-not-to-use guidance.

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