Explain Function

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

With no annotations provided, the description carries the full burden for behavioral disclosure. It does convey that the tool is read-only by saying 'Returns' and lists the main output categories, but it does not disclose behavior around absent functions, optional source annotation, or any prerequisites beyond what the schema already states.

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 two compact sentences with no filler. The first sentence front-loads the core output, and the second gives actionable usage guidance, so every sentence earns its place.

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?

The description covers the main return categories and the intended use, while the schema fully documents parameters. Since there is no output schema, a bit more detail about the exact response structure would be helpful, but the description is otherwise adequate for a focused analysis 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 explains all four parameters. The description adds no extra detail about contextLines or includeSource, and only indirectly references function lookup; it does not compensate beyond the schema baseline.

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 a specific verb and resource: 'Returns detailed timing info for a specific function: self-time, total-time, callers, and callees.' This distinguishes it from broader tools like get_hotspots, though it does not explicitly name sibling 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 phrase 'Use this to understand why a function is slow' gives clear intended usage context. However, it does not mention when not to use it or point to alternatives such as get_hotspots or suggest_optimizations, so it stops short of a full 5.

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