list_changed_files

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

With no annotations, the description carries the full burden and does disclose a meaningful behavioral trait: a hard 500-file cap and the escape hatch (path_prefix). It does not explain what happens at the cap (truncation vs. error) or any auth requirements, so it falls short of a 5.

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 short sentences, each earning its place: purpose, usage context, and limit workaround. The defining scope (two refs) is front-loaded and nothing is padding.

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-only listing tool with full schema coverage and no output schema, the description covers what is returned at a high level (changed files plus change statistics) and the cap behavior. The residual gap is only the exact response shape and cap-handling semantics.

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 base, head, owner, repo, and path_prefix are already documented. The description reinforces the path_prefix narrowing behavior but adds no syntax, default, or format detail beyond the schema – baseline 3.

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 (lists), resource (files), and scope (between two git refs, modified/added/deleted, with change statistics). This makes it clearly distinguishable from get_diff (patch content) and get_path_history (single-path history) without naming them explicitly.

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?

"Use to survey changes across commits or branches" gives clear intended context, and the path_prefix hint points at narrowing scope. It stops short of naming a sibling or a when-not condition, so it is clear but not fully routing.

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