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: the tool performs a search (implied read-only, though not explicitly stated), outputs locations (not content), and has a prerequisite ('Requires load_project to be called first'). It does not mention rate limits, permissions, or error handling, but covers essential operational context for a search tool.

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, followed by distinct sections (JDT-UNIQUE, USAGE, OUTPUT, Useful for, Requires). Each sentence earns its place by adding unique information without redundancy, and the bulleted 'Useful for' list enhances readability without verbosity.

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 2 parameters), no annotations, and no output schema, the description is largely complete: it explains the purpose, usage, output, use cases, and prerequisites. However, it lacks details on the output format (e.g., structure of returned locations) and error conditions, which could be helpful for an agent invoking the tool.

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 (typeName and maxResults). The description adds minimal value beyond the schema: it reiterates that typeName should be 'fully qualified' and implies maxResults relates to 'All locations,' but doesn't provide additional syntax, format, or constraint 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 clearly states the specific verb ('Find all usages') and resource ('type as a generic type argument'), with concrete examples (List<Foo>, Map<K, Foo>). It explicitly distinguishes this tool from LSP capabilities by noting 'JDT-UNIQUE: This fine-grained search is not available in LSP,' differentiating it from potential sibling tools like find_references or find_type_instantiations.

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: Provide fully qualified type name' and 'Requires load_project to be called first.' It also lists specific use cases ('Useful for: Understanding generic usage patterns, Finding all collections/containers of a type, API design analysis'), which helps the agent understand when to select this tool over alternatives like find_references or analyze_type.

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