expand_source

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

No annotations are provided, so the description carries the full burden for behavioral disclosure. It reveals the method ('using token-level source maps') but does not state whether the operation is read-only, what happens on missing symbols, error handling, or return format. This is a significant gap for a tool with no annotation safety net.

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 concise sentences with zero waste. The first sentence states what and how; the second gives usage guidance. Every phrase earns its place, and the structure is front-loaded with the core purpose.

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?

Despite no output schema, the tool is relatively simple and the description adequately explains its purpose and usage. The return value (full source code) is implied by the action. However, it could be slightly more complete by explicitly stating the output type or error behavior, but for the complexity level it is sufficient.

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% for all four parameters, so the baseline is 3. The description does not add any parameter-specific meaning beyond the schema; it only mentions 'symbol' generically. The schema itself clearly explains parameter usage (e.g., 'Use either symbol_id or name, not both.'), but the description contributes nothing extra.

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's function: 'Expand a symbol's compact signature to its full original source code using token-level source maps.' It uses a specific verb ('expand') and resource ('symbol's compact signature'), and distinguishes it from siblings like find_symbol and get_context by focusing on source expansion rather than lookup or context retrieval.

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 conditions for use: 'Use this when the signature is not enough and you need the implementation.' This gives clear context, but it does not mention alternatives or when not to use it, missing the 'when-not' or alternative tool guidance found in higher scores.

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