javalens-mcp

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

With no annotations provided, the description carries full burden. It discloses key behavioral traits: the tool returns 'Method signatures with parameter info' and uses 'ZERO-BASED coordinates.' It also states the prerequisite 'Requires load_project to be called first.' These are valuable beyond basic purpose. However, it doesn't mention error conditions, performance, or other operational details that could be helpful, keeping it from a 5.

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 and front-loaded with the core purpose. Each sentence earns its place: the first states what it does, the second gives usage context, the third describes output, the fourth highlights coordinate system, and the fifth specifies prerequisites. There is no wasted text, and information is presented in a logical order for quick understanding.

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 (position-based query with prerequisites), no annotations, and no output schema, the description does a good job of covering essentials: purpose, usage, output, coordinate system, and prerequisites. It doesn't explain return values in detail or error handling, which could be improved, but for a read-only tool with clear parameters, it's largely complete. The absence of output schema means some gaps remain, preventing a 5.

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 fully documents the three parameters (filePath, line, column). The description adds value by emphasizing 'ZERO-BASED coordinates,' which clarifies the semantics of line and column parameters beyond the schema's basic descriptions. This extra context is useful but not extensive, warranting the baseline 3 score when schema coverage is high.

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: 'Get method signature help at a position.' This specifies the verb ('Get'), resource ('method signature help'), and context ('at a position'). It distinguishes from siblings like 'get_method_at_position' or 'get_hover_info' by focusing specifically on signature information rather than general method or hover details. However, it doesn't explicitly contrast with all similar siblings, keeping it at 4 rather than 5.

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 clear usage context: 'Position on a method call or declaration' and 'Requires load_project to be called first.' This gives explicit prerequisites and positional guidance. It doesn't specify when NOT to use this tool or name alternatives among siblings, which prevents a score of 5. The guidance is practical but not exhaustive.

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