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

Annotations already indicate destructiveHint=true and idempotentHint=true, but the description adds important context: it can only modify draft revisions, not published ones, and it replaces the body content. It also explains that passing empty summary clears it. This goes beyond what annotations provide. The idempotentHint is consistent with the replace semantics of body_markdown, adding credibility.

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 compact, consisting of two sentences plus a tip. It front-loads the core purpose and immediately notes the critical constraint about published revisions. The recommendation for rich-text drafts is a useful addition without fluff. It could be slightly more structured but is efficient.

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 that there is an output schema (though not detailed in context signals), the description does not need to explain return values. For a mutation tool with this complexity, it covers the key constraints (draft-only, body replacement, summary clearing) and usage guidance. It is complete for an agent to decide when to invoke it.

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 schema itself already documents each parameter. The description clarifies that body_markdown is required unless only updating summary, and that summary can be cleared with empty string. However, it doesn't fully specify the side effects on existing attributes beyond body replacement, though the schema already covers that. The baseline of 3 is appropriate.

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 clearly states the specific verb 'update' and the resource (a draft document revision body and/or summary). It also differentiates itself from published revisions and mentions an alternative tool (create-document) for rich-text drafts. This distinguishes it from sister tools like publish-document-revision-tool.

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 explicitly states when to use this tool: for updating draft revisions only, and that published revisions cannot be edited and instead require creating a new draft first. It also explicitly recommends prefer rich-text drafts via create-document, giving clear alternatives for other scenarios. This is complete guidance.

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