list_host_vmks

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds substantial behavioral context: vCenter serves cached data for unreachable hosts, rows appear with reachable:false and null device, hosts_unreachable and unreachable_note fields, and truncated is a paging fact rather than an estate-completeness signal. This is exactly the kind of non-obvious behavior an agent needs to interpret results correctly.

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 long but every section earns its place: the gotcha about unreachable hosts is critical and the return-format section is dense but necessary. The '[READ]' prefix and front-loaded purpose sentence make the core action immediately clear. It could be slightly tightened, but the length is justified by the behavioral complexity it discloses.

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 read-only list tool with no output schema, the description fully compensates: it explains the envelope fields, the unreachable-host edge case, the deprecated alias, and error shape. The annotations cover safety, the schema covers parameters, and the description covers interpretation. Nothing an agent needs to call this correctly and interpret the result 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 description coverage is 100%, so the schema already documents all four parameters (limit, offset, target, host_name). The description adds the semantic nuance that host_name scopes to one ESXi host and omitting it lists across all hosts, which is already in the schema. It doesn't add new parameter-level detail beyond the schema, so baseline 3 is appropriate.

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 clear verb and resource: 'List VMkernel adapters, optionally scoped to one ESXi host.' It then enumerates the per-vmk fields returned, which distinguishes it from sibling tools like add_host_vmk/remove_host_vmk and set_vmk_service. The 'verify pair' phrasing further anchors its role relative to mutation siblings.

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?

The description explicitly states when to use it (list/verify VMkernel adapters) and names its sibling relationship: 'The verify pair for add_host_vmk/remove_host_vmk.' It also gives a strong when-not-to-trust-it warning: check hosts_unreachable before reporting the result as the full picture. This is explicit usage guidance beyond what the schema or annotations provide.

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