Multilead Open API MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the action ('send a new email') but doesn't mention authentication requirements, rate limits, error conditions, or what happens if the email fails. For a mutation tool with zero annotation coverage, this leaves significant behavioral gaps.

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 well-structured with a clear purpose statement followed by parameter documentation and return information. It's appropriately sized with no redundant information, though the 'Args' and 'Returns' sections could be integrated more seamlessly into the narrative flow.

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 tool has 6 parameters with 0% schema description coverage and no annotations, the description compensates somewhat with parameter documentation. However, as a mutation tool with behavioral implications, it lacks sufficient context about authentication, error handling, and operational constraints. The presence of an output schema reduces the need to describe return values, but overall completeness remains moderate.

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 includes an 'Args' section that documents all 6 parameters with brief explanations, providing essential semantic meaning beyond the schema's 0% description coverage. It clarifies what each parameter represents (e.g., 'signature_id: ID of the signature to use'), though it could offer more detail on format expectations or constraints.

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 tool's purpose: 'Send a new email to a recipient' with additional context about sending 'through the platform to a recipient who may not have an existing thread.' This distinguishes it from reply tools but doesn't explicitly differentiate from all sibling tools like 'send_email_reply' beyond the 'new email' vs 'reply' distinction.

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 implies usage context by specifying 'to a recipient who may not have an existing thread,' suggesting this is for initiating conversations rather than replying. However, it doesn't provide explicit guidance on when to use this versus alternatives like 'send_email_reply' or mention any prerequisites or exclusions.

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