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. It discloses key behavioral traits: it's a search tool (implied read-only), requires a project load first, and outputs methods that declare the exception. However, it doesn't mention rate limits, error handling, or pagination details beyond the maxResults parameter.

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 (description, uniqueness, usage, output, use cases, prerequisite). It's appropriately sized, but could be slightly more concise by integrating some bullet points into flowing text. Every sentence adds value, with no redundant information.

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 (search operation with prerequisites), no annotations, and no output schema, the description is fairly complete. It covers purpose, usage, prerequisites, and use cases. However, it lacks details on output format (beyond a vague statement) and error scenarios, which could enhance completeness.

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 both parameters thoroughly. The description adds minimal value beyond the schema, only reiterating 'Provide fully qualified exception type name' and implying output format. Baseline 3 is appropriate as the 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: 'Find all throws declarations of an exception type in method signatures.' It specifies the verb ('find'), resource ('throws declarations'), and scope ('in method signatures'), and distinguishes itself from siblings by highlighting its JDT-UNIQUE nature, which is not available in LSP.

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: 'Requires load_project to be called first' as a prerequisite, and lists specific use cases ('Useful for: Understanding exception flow...'). It also distinguishes from siblings by noting its unique JDT feature, though it doesn't name alternatives directly.

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