Temporal Coupling

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

The annotations already declare readOnlyHint=true, and the description adds meaningful operational context: it requires being inside a git repo (or repo_path), and it explains that findings represent co-change patterns. It doesn't contradict annotations and adds value beyond the safety annotation.

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 three sentences, front-loaded with the core verb and resource, and uses an example plus a necessary note. Every sentence earns its place, with no redundancy.

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 tool has no output schema, but the description conveys the core output concept (file pairs that change together) through the example and the parameters like limit and min_coupling. It doesn't explicitly state the return format, but for an analysis tool with good schema coverage, this is reasonably complete.

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?

All parameters are described in the schema (100% coverage), so the baseline is 3. The description reinforces the repo_path requirement and gives an intuitive example of the coupling threshold, but it doesn't add significant syntax or format details beyond the schema.

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 uses a specific verb+resource ('Find files that always change together') and clarifies that it reveals hidden dependencies not visible in imports, distinguishing it from sibling analysis tools. The concrete example (auth.ts/middleware.ts) reinforces what the tool does.

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 context for when to use the tool (identifying hidden dependencies before refactoring) and includes an operational note about repo_path. However, it does not explicitly name alternative sibling tools or state when not to use it, so it lacks explicit exclusions.

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