update_document

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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It states only that it updates an existing document, but does not disclose whether it performs partial updates (e.g., $set), what happens if the document is not found, whether the operation is atomic, or any permission requirements. 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, clear sentence with no unnecessary words and front-loads the action. It is appropriately concise, though it is so minimal that it under-specifies the tool's behavior, which is more a completeness issue than a conciseness issue.

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?

The tool is a simple update operation, but the description lacks crucial contextual details: the semantics of the update (partial vs full replacement), error handling when the document doesn't exist, and return value expectations (though an output schema exists). Given the presence of a schema and output schema, the description should at least clarify the update behavior to be minimally complete.

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 describes all three parameters (collection_name, document_id, update_json) with 100% coverage, so the baseline is 3. The description adds no additional meaning about the parameters beyond what the schema already provides, but that is acceptable given the schema's completeness.

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 identifies the resource as 'a document in a collection', which clearly distinguishes it from sibling tools like create_document, delete_document, and get_document. However, it lacks any qualifiers about the update mechanism (e.g., partial vs replace) that would add precision, so it is clear but not fully differentiated.

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 provides no guidance on when to use this tool versus alternatives. There are no exclusions, prerequisites, or alternative tool mentions. The sibling list includes create_document, delete_document, get_document, and read_collection, but the description doesn't differentiate beyond the basic action.

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