Diff two revisions

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

Annotations already declare readOnlyHint=true and the description complements this by explaining the diff output categories and the 'same entity' constraint. It does not describe error cases or edge behavior, but for a read-only diff with an output schema, the added behavioral context is sufficient.

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 with no wasted words. The first sentence states the core action and output; the second provides the practical use case. It is appropriately sized and front-loaded.

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 three fully documented parameters and an output schema, this definition is complete. It covers what the tool does, what output to expect, the same-entity constraint, and the recommended use case, with annotations covering the safety profile.

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%, with from_revision_id and to_revision_id clearly labeled as older and newer, and response_format documented with its enum. The description adds no parameter-level detail beyond the schema, but it does not need to because the schema fully covers the parameters.

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: 'Compare two saved revisions of the same entity' and specifies the output as 'added, removed and modified' field-level changes. This clearly distinguishes it from related sibling tools like get_revision or restore_revision, especially with the rollback framing.

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 gives explicit usage context: 'Use it to see what a change actually did before deciding whether to roll it back.' It does not name alternative tools or list when-not-to-use conditions, so it falls short of a 5, but the intended scenario is clear.

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