Ludus FastMCP

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states it 'List all snapshots' which implies a read-only operation, but doesn't clarify permissions, rate limits, pagination, or what 'range' refers to. The parameter note 'admin only' adds some context about authorization needs, but overall behavioral traits are minimally described.

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 appropriately concise with three sentences that each serve a purpose: stating the tool's function, describing the parameter, and indicating the return value. It's front-loaded with the main purpose. The structure with 'Args:' and 'Returns:' sections is clear, though slightly informal compared to pure natural language.

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 has an output schema (which handles return values) and only one parameter with some description coverage, the description is minimally adequate. However, for a tool with no annotations and operating in a complex environment with many sibling tools, it should provide more context about what 'snapshots' and 'range' mean in this system. The description meets basic requirements but leaves gaps in understanding the tool's full 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?

The description adds meaningful context for the single parameter: 'user_id: Optional user ID (admin only)'. Since schema description coverage is 0%, this compensates by explaining the parameter's purpose and access restriction. However, it doesn't fully explain what 'range' means in relation to the parameter. With only one parameter, the description provides adequate semantics beyond the bare schema.

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 states 'List all snapshots for the range' which provides a clear verb ('List') and resource ('snapshots'), but it doesn't differentiate from sibling tools like 'batch_remove_snapshots' or 'batch_rollback_snapshots'. The purpose is understandable but lacks specificity about what distinguishes this listing operation from other snapshot-related operations.

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 doesn't mention sibling tools like 'list_ranges' or 'list_hosts' that might be related, nor does it specify prerequisites or context for usage. The only contextual hint is in the parameter description ('admin only'), but this isn't integrated into usage guidance.

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