diffci_changed_files

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is established. The description usefully adds scope details beyond that (relative to HEAD, includes non-ignored untracked files, snapshot identity, no graph build, no tests), but says nothing about the shape of the returned data or how snapshot identity is used.

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?

Two sentences, zero filler. The scope statement is front-loaded and the exclusion clause follows immediately as supporting contrast.

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-optional-parameter read tool with no output schema, the definition covers what is enumerated and confirms the absence of side effects. It stops short of telling the agent what the return value looks like (path list format, snapshot identity field), which would be the remaining useful detail.

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?

There is a single parameter with 100% schema description coverage, including precise guidance about passing the edited repository when using a plugin. The prose adds nothing about the repo argument, so the schema carries the full burden and the baseline of 3 applies.

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 pairs a specific verb ('List') with a precisely scoped resource ('staged, unstaged and non-ignored untracked changed paths relative to HEAD') and adds a snapshot identity. The closing clause ('Builds no dependency graph and runs no tests') implicitly separates it from siblings like diffci_check and diffci_select_tests, so an agent can pick it without opening another schema.

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?

It gives clear context for when this is the right tool: the agent needs changed paths only, not a graph or a test run. The explicit exclusions act as when-not guidance, but no sibling is named as the alternative for those other needs, so routing between diffci_check and diffci_select_tests is still left to inference.

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