explain

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

The readOnlyHint annotation already covers the safety profile, and the description adds that the tool produces a summary and annotation. It does not clarify what 'annotation' means or describe any further behavioral context, but it does not contradict the annotation either.

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 that front-loads the action and the main input categories. It is appropriately concise and contains no filler, though its brevity contributes to the lack of parameter detail.

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 seven-parameter tool with no output schema, the description is under-specified: it does not explain the conditional parameter groups, the expected shape of 'diff', or what exactly the tool returns. The available annotation covers only read-only safety, not the invocation details an agent needs.

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?

With 0% schema description coverage, the description must compensate by explaining parameter meaning, but it only lists the conceptual kinds. It does not map 'uid', 'region', or 'diff' to the relevant parameters (uid vs. x/y/width/height vs. diff), leaving an agent to infer which optional parameters apply for each kind.

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 uses a specific verb ('Explain') and names the three distinct resources it handles ('uid, region, or diff'), with a clear output hint ('summary and annotation'). It distinguishes itself from the browser and task sibling tools because none of them overlap with this explanation function.

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 the tool applies by enumerating the valid input kinds, but it does not explicitly state when to prefer this tool over an alternative or when not to use it. Since no sibling tool fills a similar role, this omission is noticeable but not severely damaging.

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