nexus_create_message

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

Annotations already indicate this is a write operation with no destructive or idempotent behavior, and the description adds a small but useful return-shape detail: JSON {success} or an error string. However, it does not disclose auth requirements, rate limits, or side effects beyond the annotated basics. No contradiction with 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?

The description is tightly written: one action sentence and a clearly separated return note. No filler or redundant wording, and the main purpose is front-loaded.

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 simple 3-parameter tool with full schema coverage, an output schema, and annotations covering the safety profile, the description is largely sufficient. It could mention authentication or rate-limit expectations, but no critical information for invoking it correctly 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?

Schema description coverage is 100%, with clear descriptions for 'to', 'title', and 'body'. The description's 'one or more users' aligns with the comma-separated recipient IDs in the schema but does not add meaningful semantic value beyond it. Baseline 3 is appropriate.

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 ('Send') and resource ('private message to one or more users'), making the tool's purpose immediately clear. It also distinguishes itself from sibling read-oriented tools like nexus_get_private_message_url. The GraphQL v2 mention adds useful transport context.

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 about when to use this tool versus alternatives, nor any exclusions or prerequisites. It only restates the operation without explaining how it fits among the many sibling tools.

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