updateOne

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the destructive nature is known. However, the description adds no extra behavioral context—no mention of return value, error behavior if no document matches, or consequences of the upsert option. It contributes nothing beyond the schema and annotations.

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?

A single, clear sentence with no redundant words. It is appropriately sized for a simple tool and front-loads the core purpose.

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 mutation tool with destructiveHint, this is under-specified. There is no output schema, so the description should explain what the tool returns (e.g., modified count, updated document) and how it handles non-matching filters or upsert behavior. The tool also has nested objects, but the schema covers those. Overall, the description leaves important operational details unstated.

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 description coverage is 100%, so all four parameters (collection, filter, update, upsert) are documented in the schema. The description adds no parameter details, but the baseline of 3 applies because the schema carries the full load.

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?

States a specific verb (Update) and resource (a single document in a MongoDB collection). It clearly differentiates from read siblings (find, findOne) and delete (deleteOne) by its action, though it doesn't explicitly contrast with insertOne or mention that it targets exactly one 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?

No guidance on when to use this tool versus alternatives. It doesn't mention when to prefer updateOne over insertOne (if document may not exist), or over bulk update operations. The sibling list implies context, but the description provides no explicit routing.

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