update_documents

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

Adds beyond annotations: 'Only specified fields are updated; others remain unchanged' and 'Documents must already exist.' Consistent with idempotentHint=true. No contradictions.

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?

Well-structured with clear sections, no fluff. Every sentence adds value.

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 output schema (success/error message), description adequately covers input and behavior. However, could better contrast with sibling tools.

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?

Despite 0% schema coverage, the description provides detailed Args section explaining each parameter (collection_name, documents) and nested DocumentInput fields (id, vectors, fields). Adds significant meaning.

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?

Description clearly states 'Update existing documents by ID' and explains partial update behavior. Differentiates from siblings like insert_documents and delete_documents.

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?

Mentions documents must exist, implying not for creation, but lacks explicit guidance on when to update versus upsert or insert. No direct comparison with alternatives.

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