nexus_get_private_message_url

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds useful behavioral information beyond that by specifying the return shape: 'JSON string URL or an error string.' This gives the agent expectation about both success and failure outputs.

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, front-loaded sentences with no filler. It states the purpose first and the return type second, making it easy for an agent to parse quickly.

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 the single required parameter, clear return format, and strong annotations covering read-only/idempotent behavior, the description is complete for correct invocation. No important behavioral context is missing.

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 schema already fully documents message_id as 'Private message ID' with a minimum of 1. The description adds extra semantic value by clarifying that the ID refers to one of the authenticated user's own private messages, which is not stated in the parameter description.

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 states a specific verb and resource: 'Get the web URL for one of your private messages (v2 GraphQL).' This clearly distinguishes it from sibling URL-related tools like nexus_get_download_link or nexus_get_speedtest_urls by naming private messages as the target resource.

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 gives clear context: this tool is for private messages owned by the caller ('one of your private messages'). It does not explicitly name alternatives or when-not-to-use conditions, but the private-message scope itself provides adequate differentiation from the other get-URL tools.

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