send_simple_email

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

The description discloses that SMTP configuration falls back to environment variables if not provided, which is useful context. It also states the return type as a success or error message. Since no annotations are provided, the description carries the full burden, and while it covers the basic behavior, it does not disclose potential side effects, exclusions, or edge cases.

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 an initial one-line summary, an Args section mapping to parameters, and a Returns section. It is not overly verbose, though repeating the parameter names largely duplicates the schema. The smtp_config details are dense but relevant, and each part serves a purpose.

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 presence of an output schema and the number of parameters, the description covers the key aspects: what the tool does, the required parameters, the optional smtp_config, and the fallback behavior. It is complete enough for an agent to understand how to invoke the tool correctly, though it leaves room for more detail on error conditions and rate limits.

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 schema has 0% description coverage, so the parameter descriptions in the docstring add crucial value, especially for smtp_config, which is only typed as an arbitrary object in the schema. The description explains each expected sub-field of smtp_config and the fallback behavior of environment variables. However, the descriptions for to, subject, and body add little beyond their names.

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 operation: 'Send a simple email.' The verb 'send' and resource 'simple email' are explicit, and the name is distinct from the sibling send_custom_email by the modifier 'simple', which implies it's for basic emails. However, it does not explicitly contrast itself with send_custom_email, so the differentiation is implicit.

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 gives no explicit guidance on when to use this tool versus alternatives such as send_custom_email or test_smtp_connection. It does mention the optional smtp_config override and fallback to environment variables, but this is parameter context rather than usage-selection guidance. The sibling tools are not mentioned or compared at all.

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