list_fc_adapters

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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds substantial context beyond them: the hosts_not_read contract ('never report it as having no FC adapters'), the speed_reported caveat that vSphere reports Gbit/s despite documented bits-per-second, and that it reads host config only with no rescans. These are exactly the behavioral traps an agent needs to avoid misreporting.

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 purpose and usage in the first two sentences, then the return-shape and caveat details. Dense and mostly waste-free, though the block is long enough that the hosts_not_read and speed_reported caveats could be tightened slightly.

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 carries the return burden and does so: it documents the list envelope (items, returned, total, truncated, next_offset) plus the two non-obvious extra fields (hosts_without_fc, hosts_not_read with reason). Nothing an agent needs to call and interpret this tool correctly is missing.

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%, so the documented parameters already stand on their own (limit, offset, next_offset paging, exact-match naming). The description still adds value by clarifying the precedence between cluster, host, and target ('with neither, every host on the target is read') and by noting the operation stays cheap at that scope.

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 opens with a specific verb+resource ('List Fibre Channel HBAs (FC and FCoE) per ESXi host') and enumerates the returned fields (vmhba, model, driver, status, port type, WWPN/WWNN, link speed). It explicitly distinguishes itself from the sibling list_storage_device_paths, so an agent can route correctly without reading either schema.

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?

It gives concrete use cases in the user's own words ('which FC adapters does each host have', 'to find a host's WWPNs') and names the alternative (list_storage_device_paths) with the condition that selects it (devices and paths behind the adapters). Scope semantics (cluster OR host; neither = all hosts on target) are also spelled out.

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