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 this 'starts testing state' which implies a state change operation, but doesn't clarify what permissions are needed, whether this is reversible, what side effects occur, or what happens to the range during testing. The mention that user_id is 'admin only' is helpful but insufficient for a mutation tool with no annotation coverage.

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 short sentences. It's front-loaded with the main purpose, followed by parameter and return value sections. No wasted words, though the initial purpose statement could be more 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?

For a tool that presumably changes system state (starting testing), with no annotations and minimal parameter documentation, the description is inadequate. While there's an output schema (which reduces need to describe returns), the description doesn't explain what 'testing state' entails, what gets affected, or how this interacts with other range operations. Given the complexity implied by sibling tools and the lack of behavioral context, this is incomplete.

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 provides a brief parameter explanation: 'user_id: Optional user ID (admin only)'. With 0% schema description coverage and only 1 parameter, this adds meaningful context about the parameter being optional and admin-restricted. However, it doesn't explain what happens when user_id is null vs provided, or how this affects the testing process.

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 'Start testing state for the range' which is a tautology that essentially restates the tool name 'start_testing'. It doesn't specify what 'testing state' means, what kind of testing, or what 'range' refers to in this context. While it mentions a verb ('Start') and resource ('testing state for the range'), it's too vague to be genuinely helpful.

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. There's a sibling tool called 'stop_testing' that appears related, but the description doesn't mention it or explain when to start vs stop testing. No prerequisites, timing considerations, or alternative approaches are mentioned.

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