Debugging MCP Server

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

With no annotations provided, the description carries full burden and does well. It discloses that the tool requires an active DAP connection and works best when debuggee is stopped. It explains the behavioral difference between 'hover' (safe, no side effects) and 'watch' (read-only but different formatting). However, it doesn't mention potential limitations like expression complexity constraints or error handling.

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?

Three sentences with zero waste. First sentence states purpose, second provides prerequisites and optimal conditions, third explains the key parameter distinction. Every sentence earns its place and information is front-loaded appropriately.

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?

For a debug expression evaluation tool with no annotations and no output schema, the description does well. It covers prerequisites, optimal conditions, and key parameter semantics. However, without an output schema, it doesn't describe what the evaluation returns (values, errors, formats), which would be helpful for 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 baseline is 3. The description adds some value by explaining that 'context' restricts evaluation type and distinguishing between 'hover' and 'watch', but doesn't provide additional semantic context beyond what's already in the schema descriptions. The schema already documents all parameters thoroughly.

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 verb 'evaluates' and resource 'expression' with context 'in the context of the debuggee's current state'. It distinguishes from siblings like 'step_debugger' or 'inspect_runtime_state' by focusing specifically on expression evaluation rather than debugging control or state inspection. However, it doesn't explicitly contrast with all possible alternatives.

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 when-to-use guidance: 'Requires an active DAP connection and typically works best when the debuggee is stopped.' It also distinguishes between 'hover' (default, safe) and 'watch' contexts, giving clear operational context. The prerequisites are clearly stated.

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