Ludus FastMCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that 'user_id' is 'admin only', hinting at permission requirements, but fails to cover critical aspects like whether this is a destructive operation, rate limits, error handling, or what 'Snapshot scheduling result' entails. For a mutation tool with zero annotation coverage, this is a significant gap in transparency.

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 well-structured with a clear purpose statement followed by 'Args' and 'Returns' sections. It is front-loaded and efficient, with each sentence adding value. However, the 'Returns' section is vague ('Snapshot scheduling result'), which slightly reduces conciseness by not being fully informative.

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?

Given the tool's complexity (scheduling snapshots with 4 parameters), no annotations, and an output schema that likely details the return value, the description is moderately complete. It covers parameters well but lacks behavioral context and usage guidelines. The output schema may mitigate the need to explain return values, but overall, it falls short of being fully comprehensive for a mutation tool.

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?

With schema description coverage at 0%, the description compensates by explaining all four parameters: 'vm_names' as a list of VMs, 'schedule' as a cron expression, 'retention_count' as the number to retain, and 'user_id' as optional and admin-only. This adds meaningful semantics beyond the bare schema, though it could provide more detail on cron format or retention behavior.

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's purpose: 'Schedule automatic snapshots for VMs.' It specifies the verb ('schedule') and resource ('snapshots for VMs'), making the action explicit. However, it does not distinguish this tool from sibling tools like 'snapshot_host' or 'batch_snapshot_hosts', which appear to handle snapshot operations differently, so it misses full sibling differentiation.

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 provides no guidance on when to use this tool versus alternatives. It lacks context on prerequisites, such as VM availability or permissions, and does not mention sibling tools like 'snapshot_host' or 'batch_snapshot_hosts' for comparison. This absence of usage instructions leaves the agent without clear direction for tool selection.

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