Compare two versions

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

Annotations already declare readOnlyHint=true, covering the safety profile. The description adds behavioral context: it returns a unified diff, treats an omitted to_version as a comparison against the live page, and collapses two page-body reads into one call. It doesn't discuss output formatting details or limits, so a 3 is appropriate.

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 dense, front-loaded sentences with no filler. The first sentence states the core behavior and the optional mode; the second justifies the tool's value without repeating the schema.

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?

Given the readOnly annotation, complete parameter schema, and simple scalar inputs, the description supplies enough context for correct invocation. With no output schema, naming the result as a 'unified diff' and covering the live-page comparison makes the return behavior sufficiently clear.

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 baseline is 3 and the description need not document parameters. The one parameter behavior it mentions (omitting to_version compares with the live page) is already present in the schema's to_version description.

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 clearly identifies the operation: returns a unified diff between two page versions, with an optional live-page comparison. It doesn't name a sibling explicitly, but the verb+resource and the 'instead of two full page bodies' phrase make the purpose unambiguous compared with get_page_version and list_page_history.

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 a clear use case — answering 'what changed here' efficiently — and implicitly contrasts with fetching two full page bodies. It stops short of naming sibling tools or stating when not to use it, so the guidance is good but not exhaustive.

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