vm_list_ttl

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, and the description adds meaningful behavior beyond that: it reads the entire TTL store, describes the list envelope fields, and explicitly explains that truncated is always false. This gives the agent a precise model of what the call will return and how the data behaves.

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 compact and front-loaded: purpose first, then the key usage hint, then return format. Every sentence adds useful information and there is no filler or repetition of schema details.

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 parameterless read-only list tool, this is complete. It names the output envelope, the important fields (remaining_minutes, expired flag, returned/total/truncated), and the invariant that truncated is always false. The lack of an output schema is compensated by the description's return-value detail.

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?

The tool has zero parameters and the schema already documents this fully, so the description does not need to add parameter guidance. The description instead intelligently emphasizes output semantics, which is the relevant semantic burden for a no-argument list tool.

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 uses a specific verb and resource: 'List all VMs with TTLs registered, including expiry time and status.' It clearly distinguishes itself from related TTL manipulation tools by stating it is the read-oriented listing operation and 'Use this first to find the exact vm_name for vm_cancel_ttl.'

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 gives an explicit use case: use this tool first to discover the exact vm_name needed by vm_cancel_ttl. It provides clear context for when to invoke it, though it does not explicitly state when not to use it or name broader alternatives.

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