javalens-mcp

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

No annotations are provided, so the description carries the full burden. It discloses key behavioral traits: it requires a loaded project ('Requires load_project to be called first'), uses zero-based coordinates ('IMPORTANT: Uses ZERO-BASED coordinates'), and outputs a list ('OUTPUT: List of methods that call this method'). However, it lacks details on error handling, performance, or rate limits, which are minor gaps.

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, usage, output, important note, use case, prerequisite). Each sentence adds value: the first states the purpose, the second gives usage instructions, the third specifies output, the fourth highlights a critical detail, the fifth explains when to use it, and the sixth notes a prerequisite. It is front-loaded and waste-free.

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 complexity (static analysis with prerequisites), no annotations, and no output schema, the description does well by covering purpose, usage, output format, coordinate system, use case, and prerequisite. However, it could improve by detailing error scenarios or the structure of the output list, but it's largely complete for agent understanding.

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 parameters (column, line, maxResults, filePath). The description adds minimal value beyond the schema, mentioning 'ZERO-BASED coordinates' which aligns with the schema's descriptions but doesn't provide additional syntax or format details. This meets the baseline for high schema coverage.

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 explicitly states the tool's purpose: 'Find all callers of a method (incoming calls).' It specifies the verb ('find'), resource ('callers of a method'), and scope ('incoming calls'), clearly distinguishing it from its sibling 'get_call_hierarchy_outgoing' which presumably finds outgoing calls. This is specific and avoids tautology.

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 guidance: 'USAGE: Position cursor on a method name' and 'Requires load_project to be called first.' It also states when to use it: 'Useful for understanding who depends on a method before changing it.' This covers prerequisites, context, and purpose, offering clear when-to-use instructions.

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