select_email

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

There are no annotations, so the description carries the full burden of disclosing side effects and behavior. It does not state that selection is persisted or affects subsequent send_email calls, what happens on invalid ids, whether 'fixed' is a literal accepted value, or any output/return behavior.

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 a single concise sentence and gets to the point quickly. It could be clearer, especially around 'fixed' and emailAddress, but there is no wasted text.

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 mutable/stateful selection tool with no annotations and no output schema, the description is too thin. It lacks the tool's side effects, prerequisites, accepted special values, and parameter meanings, leaving important gaps for an agent trying to use it correctly.

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 0%, so the description must compensate. It adds meaningful semantics for emailId by saying it can be an id from list_emails or 'fixed'. However, the optional emailAddress parameter is left completely unexplained, and the relationship between the two parameters is unclear.

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 uses a specific verb ('Select') and identifies the target resource ('mailbox address to send from'), which clearly distinguishes it from sibling tools like list_emails or send_email. However, the meaning of the quoted 'fixed' value is ambiguous and not fully explained.

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 phrase 'to send from' implies this tool is used before sending email, and the reference to list_emails suggests where the id comes from. But there is no explicit when-to-use/when-not-to-use guidance, no mention of prerequisites like authentication, and no direct comparison to alternatives.

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