javalens-mcp

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

With no annotations provided, the description carries full burden and adds valuable behavioral context: it discloses that the tool is 'Much faster' (performance trait), outputs 'Syntax errors (no semantic analysis for speed)' (scope limitation), and has a prerequisite ('Requires load_project'). It doesn't mention error formats, rate limits, or auth needs, but covers key operational aspects beyond basic function.

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 front-loaded with purpose, followed by usage, output, comparison, and prerequisite in separate lines. Every sentence earns its place: no redundancy, each adding distinct value (e.g., speed comparison, load_project requirement). It's efficiently structured without wasted words.

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 no annotations and no output schema, the description compensates well by explaining the tool's behavior (fast, syntax-only), usage context, and prerequisite. It doesn't detail output format or error types, which is a minor gap, but for a validation tool with good schema coverage and clear guidelines, it's largely complete and actionable.

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. The description adds minimal param semantics by showing usage examples ('validate_syntax(filePath="...") or validate_syntax(content="...")') and implying mutual exclusivity, but doesn't elaborate on format or constraints beyond what the schema provides. 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 performs 'syntax-only validation for a file or inline code' with 'no semantic analysis for speed', specifying both the action (validation) and resource (file/code). It distinguishes from sibling 'get_diagnostics' by emphasizing speed and scope, making the purpose specific and differentiated.

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 explicitly states 'Much faster than get_diagnostics - use for quick syntax checks' and 'Requires load_project to be called first', providing clear when-to-use guidance (quick checks vs. diagnostics) and a prerequisite. It names an alternative tool and specifies a required prior action, covering both usage context and exclusions.

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