affected_files

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

With no annotations, the description carries the burden and does disclose useful behavior: it includes test files and is intended for pre-test execution. However, it does not state that the operation is read-only, what the return structure looks like, or whether it traverses the full dependency graph (despite max_depth being an input). This is adequate but not rich.

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 tight sentences: the first states the core function, the second adds the test-file detail, and the third gives the operational context. There is no wasted text, and the most identifying information is front-loaded.

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 read-style query tool with fully documented parameters, the description is nearly complete: it explains the tool's purpose, a key behavioral feature (test files), and the practical context. The only missing context is an explicit statement about the return value format and exclusions vs alternatives, but the tool is simple enough that this does not block correct invocation.

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 each parameter is already documented. The description adds no extra parameter-level meaning beyond implying the main input is a changed file path, which aligns with the schema. Baseline 3 is appropriate.

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 states a specific verb ('Find'), a specific resource ('all files affected by a change to a specific file or symbol'), and a notable inclusion ('test files'). It clearly distinguishes this tool from sibling search tools like get_dependents or get_file_context by emphasizing test-file coverage and its purpose for test execution.

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 an explicit when-to-use context: 'Use this before running tests to know which test files to execute.' This is clear context, though it does not explicitly name alternatives or state when not to use this tool versus impact_analysis or simulate_change.

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