x-ai-mcp

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It successfully indicates this is a write operation ('Send') and specifies authentication requirements ('Requires OAuth with dm.write scope'), which are crucial behavioral traits. However, it doesn't mention other important aspects like rate limits, message length constraints, or what happens if the user_id is invalid.

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 perfectly structured with a clear purpose statement upfront, followed by authentication requirements, then parameter explanations. Every sentence earns its place - the first establishes what the tool does, the second provides critical usage context, and the parameter section adds necessary clarification. No wasted words.

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 this is a write operation with no annotations but with an output schema (which handles return values), the description provides good coverage of the essential aspects: purpose, authentication requirements, and parameter semantics. It could be more complete by mentioning behavioral constraints like message length limits or error conditions, but covers the core functionality adequately.

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 description adds meaningful context for both parameters beyond the schema's 0% coverage. It explains that 'user_id' represents 'The recipient's user ID' and 'text' represents 'Message text,' providing essential semantic understanding that the schema alone (with just titles 'User Id' and 'Text') doesn't convey. This compensates well for the low schema coverage.

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 specific action ('Send a direct message') and resource ('to a user'), distinguishing it from sibling tools like x_dm_inbox, x_list_dms, or x_read_dm which handle reading DMs rather than sending them. The verb+resource combination is precise and unambiguous.

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 clear context by stating 'Requires OAuth with dm.write scope,' which indicates when this tool can be used (when proper authentication is available). However, it doesn't explicitly mention when NOT to use it or name alternatives like x_post_tweet for public messages, leaving some room for improvement in sibling differentiation.

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