send_email

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

With no annotations provided, the description carries full burden but provides minimal behavioral information. It mentions the transport mechanism ('via SMTP') and shows a default sender name, but doesn't disclose important behavioral traits like authentication requirements, rate limits, error conditions, whether emails are queued or sent immediately, or what happens with invalid addresses. The 'Returns' section is vague about what 'details' includes.

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 clear sections (purpose, args, returns, example) and efficiently communicates essential information. The example is helpful but could be more concise. Some sentences like 'Send an email via SMTP' are perfectly efficient, while the example shows multiple parameters that could be trimmed.

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 5-parameter mutation tool with no annotations but with output schema, the description covers the basic purpose and parameters adequately. However, it lacks important context about behavioral implications (side effects, error handling, authentication needs) that would be crucial for safe usage. The presence of an output schema reduces the need to document return values, but other gaps remain significant.

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?

With 0% schema description coverage, the description compensates well by providing clear parameter documentation in the 'Args' section, including data types, optionality, and default values. It adds meaningful context beyond the bare schema, explaining that 'cc' accepts comma-separated addresses and 'from_name' has a specific default. However, it doesn't explain format constraints (e.g., email validation) or provide examples for complex cases.

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 an email via SMTP') and resource ('email'), distinguishing it from sibling tools like list_emails or read_email. It provides a concrete verb+resource combination that leaves no ambiguity about the tool's function.

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 on when to use this tool versus alternatives like list_emails or search_emails. There's no mention of prerequisites, appropriate contexts, or when other email-related tools might be more suitable. The example shows usage but doesn't explain context.

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