arch_diff

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It usefully states that the tool is read-only and describes the diff output as added/removed nodes and edges, but it omits details such as error behavior, permissions, or whether any limits apply beyond the schema-documented max_bytes.

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 tight sentence plus 'Read-only', with the core action and output front-loaded. There is no unnecessary wording and every clause contributes useful information.

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 diff tool with a fully described schema and no output schema, the description covers the essential action, accepted refs, and returned difference categories. It is largely complete, though it could say more about error or truncation behavior when max_bytes is exceeded.

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%, and the schema already documents from, to, max_bytes, and workspace. The description repeats the ref values but adds no meaning beyond what the schema provides, so the baseline score 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 states a specific verb and resource: diffing two snapshots and returning added/removed nodes and edges. Its purpose is clear, but it does not explicitly distinguish itself from siblings such as arch_status or arch_snapshot.

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 implies when to use the tool by explaining that it diffs snapshots and accepts current, git HEAD, or snapshot_id refs. However, it gives no explicit guidance on when to choose this over related tools like arch_snapshot or arch_status, and no exclusions are stated.

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