Send an email

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

Annotations already indicate destructiveHint=true and idempotentHint=false. The description adds value by explicitly stating the daily send limit and explaining the base64-to-multipart attachment handling, which goes beyond what annotations provide. However, it does not disclose potential side effects like the email actually being sent irrevocably.

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 compact with four sentences. The first sentence states the purpose, followed by constraint and technical detail. No redundant information. It is well-structured and front-loaded for quick comprehension.

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's complexity (9 parameters, no output schema) and presence of annotations, the description covers the key constraint and attachment handling but lacks information on return values, error conditions, or post-send behavior. An agent might need additional context to use the tool reliably without errors.

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 67%, so the description adds some context (e.g., attachments as base64) but does not significantly enhance understanding of parameters beyond the schema. The description clarifies the attachment format but does not explain 'replyToId' or 'bcc' more than the schema.

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 an email through one of the user's mailboxes.' It identifies the specific verb (send) and resource (email), and adds context about mailboxes and daily limits. This distinguishes it from sibling tools like qmailing_get_email and qmailing_list_emails.

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 mentions the daily send limit but does not provide explicit guidance on when to use this tool versus alternatives, such as when to use other sending or email-related tools. There is no mention of prerequisites or scenarios where this tool should be avoided.

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