emacs_ediff_files

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

No annotations are present, so the description carries the full burden of behavioral disclosure. It says the tool returns the diff, but does not disclose whether it launches an interactive Ediff session, returns plain text, requires existing files, or how format and context_lines affect execution. This is minimal disclosure.

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?

One sentence with no filler, front-loaded with the action and object, and ending with the result. Every word contributes to the tool's meaning.

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 core purpose and the returned diff are stated, and the parameter schema fills in format and context-line details. However, with no annotations and no output schema, the description leaves ambiguity about interactive versus non-interactive behavior and does not route the agent among the many diff-related siblings.

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 the schema already documents file_a, file_b, format, and context_lines. The description adds no parameter-level meaning beyond what the schema provides, so the baseline of 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?

Description states a clear verb ('Compare'), resource ('two files'), and result ('return the diff'), which helps distinguish it from buffer- and region-based ediff siblings. It does not explicitly contrast with emacs_git_diff or emacs_diff_summary, but the two-file scope is reasonably specific.

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?

No guidance is provided on when to choose this tool over the many diff-related siblings such as emacs_git_diff, emacs_ediff_buffers, emacs_ediff_regions, or emacs_diff_summary. Usage is only implied by the action 'Compare two files'; no exclusions or preconditions are stated.

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