evaluate_on_call_frame

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

No annotations provided, so description carries full burden. It discloses side effects: read-only by default but can modify state if expression includes mutations. Also mentions prerequisite (paused debugger) and return value. Lacks details on error conditions or permission requirements, but sufficient for a debugging 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?

Description is concise, with separate lines for side effects, prerequisites, return, and alternatives. The core purpose is front-loaded. Minor redundancy in side effects line ('read-only by default; can modify state if expression includes mutations') could be tightened, but overall well-structured.

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 single-parameter tool with no output schema, the description adequately covers purpose, side effects, prerequisites, return value, and alternatives. No gaps detected.

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 covers the single parameter 'expression' with description. The tool description adds context about scope access and preconditions ('accessing local variables and call stack'). Schema coverage is 100%, so baseline is 3; description adds value beyond schema, hence 4.

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 it evaluates JavaScript expressions within a paused call frame's scope, accessing local variables and the call stack. It distinguishes from sibling tools like 'evaluate_js' (global scope) and 'step_over' (advance without evaluation).

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?

Explicitly states when to use: 'Use this to inspect variables and call stack during debugging.' Provides alternatives: 'evaluate_js' for global scope, 'step_over' to advance. Also notes prerequisite: debugger must be paused.

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