list_all_datastores

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. The description adds useful behavioral context beyond these, such as the [READ] tag, the one-pass enumeration guarantee ('Enumerated in one pass, so truncated is always false'), and the return envelope structure. This enriches the agent's understanding without contradicting annotations.

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 front-loaded with the purpose and followed by usage guidance and return details. Each sentence provides value, though the 'Args' block slightly duplicates what the schema shows. Overall it is appropriately sized for the tool's simplicity.

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 simple read-only list tool with one optional parameter and no output schema, the description covers the purpose, usage, return envelope, and truncation behavior. It also explains how this tool fits into workflows with sibling tools, making it fairly complete.

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 0%, but the description compensates by explaining that 'target' is an optional vCenter/ESXi target name from config. This adds meaning the schema lacks (which only provides a title and default). The definition is sufficient for the single parameter.

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 tool lists all datastores with capacity, usage percentage, and accessibility. It also distinguishes itself from siblings by noting it's the first step for obtaining ds_name used by browse_datastore and scan_datastore_images.

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 instructs 'Use this first for the ds_name that browse_datastore and scan_datastore_images require', giving a concrete when-to-use scenario and naming the sibling tools that depend on it. This provides clear usage guidance beyond what the schema or annotations offer.

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