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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does state that content replaces the entire document body, but this is also already documented in the input schema's property description. The description does not mention permissions, reversibility, side effects, or what happens to other fields when only title or content is supplied. This 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 a single sentence of 17 words, immediately front-loading the verb and object. It includes the essential scope ('doc, word, note') and the key action ('replace the body') with no filler or redundant phrasing. Every part earns its place.

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's simplicity (3 parameters, no output schema) and the strong schema coverage, the description is largely sufficient. It covers the core update capability and the destructive nature of content replacement. It could mention that id is required and other fields are optional, but this is already clear from the schema. Overall, it is complete enough for an agent to use correctly.

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 100%, so the baseline is 3. The description adds the 'and/or' qualifier, indicating that a call can include title, content, or both, which is a useful usage pattern not explicitly stated in the schema. However, the schema already provides clear descriptions for each parameter (e.g., 'New HTML content (replaces entire document body)'), so the description's additional value is marginal.

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 states the specific verb 'Update' and the resource 'existing document', further distinguishing it as handling doc, word, and note types. This clearly differentiates it from sibling tools like update_sheet or update_slide_presentation. The additional clause about supplying title and/or HTML content to replace the body further clarifies the tool's scope.

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 usage by mentioning 'existing document', which signals this is for modifying already-created documents rather than creating new ones. However, it lacks explicit when-to-use or when-not-to-use guidance and does not name any alternative tools (e.g., create_document or delete_document). The context is clear but not fully explicit.

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