javalens-mcp

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behaviors: returns a text edit (not applying it directly), uses zero-based coordinates, and has specific requirements about the anonymous class structure. However, it doesn't mention error handling, performance characteristics, or what happens if requirements aren't met.

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 clear sections (purpose, returns, usage, output, coordinate system, requirements, dependencies). Each sentence adds value, though the 'OUTPUT' line is somewhat redundant with 'Returns' and 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?

Given the tool's moderate complexity (refactoring operation with specific requirements), no annotations, and no output schema, the description does a good job covering purpose, usage, prerequisites, and behavioral context. It explains what the tool returns and how to use it, though could benefit from more detail about the edit format or error cases.

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 100%, so the schema already documents all three parameters (filePath, line, column). The description adds context about zero-based coordinates and positioning on the 'new' keyword, but doesn't provide additional syntax or format details beyond what the schema provides. Baseline 3 is appropriate when schema does the heavy lifting.

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: converting an anonymous class to a lambda expression. It specifies the exact action ('convert'), the resource ('anonymous class implementing a functional interface'), and distinguishes it from siblings by focusing on this specific refactoring operation, unlike general analysis or other refactoring tools.

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 explicit usage instructions: position cursor on the 'new' keyword, requires load_project first, and specifies prerequisites (anonymous class must implement a functional interface). It clearly indicates when to use this tool versus alternatives by defining the exact scenario and dependencies.

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