Send an email

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

Annotations indicate non-read-only, non-destructive, open world. Description adds that 'from' is fixed and attachments must be base64-encoded, but does not disclose authentication needs, rate limits, or success/failure behavior. Some value added beyond 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?

Two sentences, no redundancy, every word adds value. Front-loaded with verb and resource.

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?

With 8 parameters, no output schema, and many sibling tools, the description covers core sending functionality but lacks details on error handling, attachment limits, or whether multiple recipients are supported. Adequate but not comprehensive.

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 coverage is only 13% (only 'to' described). Description clarifies that text or html can be provided, and attachments need base64 encoding. However, it omits semantics for cc, bcc, reply_to, and subject. Partially compensates for 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 tool sends an email via Proton Bridge SMTP, identifies the key constraints (fixed from, text/html/both, base64 attachments), and distinguishes it from sibling tools like reply or forward by naming the method.

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 for sending new emails but does not explicitly state when to use this tool over siblings (e.g., reply, forward) or provide any exclusion criteria. No alternative tools are mentioned.

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