emacs_ediff_buffers

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

With no annotations, the description carries the full burden of behavioral disclosure. It only says 'Compare two buffers and return the diff'; it does not state whether buffers are modified, whether an interactive Ediff session is started, or whether buffers must already exist. Given that 'ediff' in Emacs usually implies interactive behavior, this ambiguity is significant.

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 a single sentence with no wasted words and the main action is front-loaded. It is appropriately terse, though it sacrifices useful behavioral and usage context for brevity.

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?

Without an output schema or annotations, the description should at least clarify the return value's nature and any side effects. While the schema documents format and context_lines, the description does not make clear whether the result is a textual diff string or an interactive Ediff buffer, leaving a meaningful completeness gap.

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?

The input schema provides 100% parameter coverage, so the baseline is 3. The description adds no extra meaning for buffer_a, buffer_b, format, or context_lines beyond what the schema already documents.

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 clear action ('Compare'), a specific resource ('two buffers'), and an outcome ('return the diff'). It is distinguishable from sibling tools like emacs_ediff_files and emacs_ediff_regions by naming buffers as the target, though it does not explicitly contrast with those alternatives.

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 no guidance on when to use this tool versus emacs_ediff_files, emacs_ediff_regions, or emacs_ediff_3way. The intended scope is only implied by the tool name and the phrase 'two buffers', but no explicit when-to-use or alternative routing is given.

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