Update Document

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

With no annotations, the description carries the full burden of behavioral disclosure. It usefully states that 'Only supplied fields change', which clarifies the partial-update semantics. However, it does not disclose whether passing null values clears fields, how missing documents are handled, or whether validation rules apply to particular fields—important behavior 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 with no filler. It front-loads the action and resource, then adds the key partial-update behavior. Every clause contributes useful information.

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 tool with 8 parameters and no annotations or schema descriptions, this description is too thin. It does not address null semantics, nested object formats, missing-document errors, or tie the tool into the overall Mendeley workflow relative to siblings. While an output schema exists, the input-side ambiguity remains unresolved.

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 0%, so the description must compensate for parameter meaning. It lists several field names (title, authors, year, etc.), but it does not explain the expected format for nested structures like 'authors' (array of objects) or 'identifiers' (object of strings), nor does it mention default/null behavior. This leaves significant gaps for an agent trying to construct correct arguments.

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 clearly states the action ('Update'), the resource ('an existing library document'), and lists the specific fields affected: title, authors, year, source, abstract, or identifiers. This makes it easy to distinguish from sibling tools like mendeley_add_document or mendeley_delete_document without needing to inspect the schema.

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 'on an existing library document' implies the tool is for modifying already-created documents, which is a reasonable usage hint. However, it does not explicitly state when to prefer this over alternatives like mendeley_add_document, nor does it mention any exclusions or preconditions (e.g., whether partial updates are supported when only some fields are supplied).

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