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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely useful context beyond structure: the auth requirement ('Needs the user's Cotlet API key with access to this app') and the domain rule that 'None is always allowed for costs such as rent.'

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?

Front-loaded with purpose, then usage routing, then behavioral rules. Every sentence adds information, though the leading 'Dext:' prefix largely restates the title and is mildly redundant.

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 zero-parameter, read-only lookup whose safety profile is already carried by annotations, the description supplies everything an agent needs: what it returns, how to consume the owner_id, an auth requirement, and the 'None' edge case.

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 tool takes zero parameters, so there is nothing to document and no gap for the description to fill. Baseline 4 applies for a parameterless operation.

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+resource ('Users you can assign as document owner') and clarifies the exact scope ('the users shown in the Document owner dropdown of Add documents'). An agent can immediately distinguish this from sibling tools like dext_upload_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?

Explicitly tells the agent how to use the output: 'Use the owner_id as document_owner in upload_document,' routing to the sibling that consumes this data. It lacks an explicit when-not clause, but the before-upload context is unambiguous.

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