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

Without annotations, the description carries the disclosure burden. It discloses two important behaviors: ownership is a precondition, and omitted fields retain their current values (partial update). However, it does not disclose expected return value, error behavior, or potential side effects, which is a significant gap for a mutation tool.

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 two short sentences, front-loaded with the core action, and every phrase adds value. It avoids restating the schema or including irrelevant 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?

Given the tool has 9 parameters, no output schema, and no annotations, the description is minimal but covers the key behavioral rule (omit to keep). However, it fails to mention what the tool returns after a successful update, and does not clarify edge cases such as interactions between visibility and allowed_domain, or whether updating an archived document is allowed. The rich schema compensates for some, but not all, missing context.

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?

The input schema already describes each parameter in full (100% coverage), so the baseline is 3. The description adds valuable cross-parameter semantics: 'Omit any field to keep its current value' clarifies that all fields except slug are optional and that partial updates are supported. This goes beyond what the schema says individually.

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 ('Update') and resource ('existing document') and adds an important ownership qualifier ('you own'). This clearly distinguishes it from sibling tools like create_document, get_document, and archive_document.

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 phrase 'you own' gives clear context for when to use the tool, but it does not explicitly mention alternatives or when not to use it (e.g., archived documents). There is no guidance on sibling tools like archive_document or create_document, so usage is implied rather than explicit.

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