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

Annotations already carry readOnly=false, destructive=false, idempotent=false, so the description adds useful patch semantics rather than redisclosing safety. It explains omitted files are carried forward, previous versions are immutable, and the response includes the new version and preview_url. This clarifies behavior beyond a mere mutation label.

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?

Five short sentences, each with a distinct job: trigger, prerequisite, action, patch behavior, retention, return value. Front-loaded with the when-to-use condition, zero filler.

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 2-param update tool with no output schema, the description fully covers invocation flow, versioning, and return value. An agent can call it correctly without needing additional information beyond the schema and annotations.

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 coverage is 0%, so the description carries the burden for the two parameters. It explains the lifecycle behavior of `files` (sent files become a version, omitted files carry forward), but it never names `draft_id` explicitly or gives structure for path/content; those are obvious from the schema but not documented in prose. Adequate compensation for a small, self-descriptive schema.

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?

Clear verb+resource: 'Update files in an existing draft.' The phrase 'draft already exists' differentiates it from create_draft, and the mention of copy, sections or layout clarifies scope. No ambiguity.

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?

Explicit when-to-use: 'Use this when a draft already exists and the user asks to change its copy, sections or layout.' It also gives a concrete prerequisite: call get_draft first if current text isn't available, which routes the agent to the correct sibling.

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