Ludus FastMCP

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

With no annotations, the description carries full burden but provides minimal behavioral context. It mentions parallel execution and admin-only restriction for user_id, but lacks details on permissions, error handling, rate limits, or what 'Results for each VM' contains. For a mutation tool with zero annotation coverage, this is inadequate.

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?

Well-structured with clear sections (description, Args, Returns, Example). The description is front-loaded with the core purpose. The example is helpful but could be more concise. Overall efficient with minimal waste.

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 mutation tool with no annotations and no output schema, the description is incomplete. It lacks crucial behavioral details (permissions, side effects, error handling) and doesn't explain the return format beyond 'Results for each VM'. The example helps but doesn't compensate for missing context.

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 0%, but the description explicitly documents both parameters in the Args section, explaining vm_names as 'List of VM names to power on' and user_id as 'Optional user ID (admin only)'. This adds meaningful semantics beyond the bare schema, though format details remain unspecified.

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 action ('Power on') and resource ('multiple VMs'), specifying parallel execution. It distinguishes from obvious siblings like 'batch_power_off_hosts' by stating the opposite action, though not explicitly naming alternatives.

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 implies usage for powering on multiple VMs in parallel, but doesn't explicitly state when to use this vs. single-VM tools or other batch operations. The 'admin only' note for user_id provides some context but not comprehensive guidance on tool selection.

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