set_email_user

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

With no annotations provided, the description must carry the burden of transparency. It mentions 'for the current session,' hinting at session-scoped persistence, but does not disclose whether the operation is idempotent, requires authentication, or has side effects on existing email data.

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, clear sentence with no redundant words. It is appropriately front-loaded and efficient.

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 simple single-parameter tool, the description gives the core purpose and scope (session). However, it lacks any context on how this relates to sibling tools (e.g., whether 'get_email_address' will reflect this change) or what happens after setting. No output schema is provided, so the description should at least hint at the result or side effects.

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 100%, so the description adds minimal extra meaning beyond the parameter's own description ('Desired local part (before the @)'). The tool description restates 'local part' but does not provide new semantic details like format constraints or examples.

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 the specific verb 'Set' and clearly identifies the resource as 'the local part of the email address for the current session.' It effectively distinguishes from sibling tools like 'check_inbox' and 'get_email_address' which handle different aspects of email.

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 the tool is used to configure the email local part for the session but provides no explicit guidance on when to use it versus alternatives, nor does it mention prerequisites or exclusions. Usage is implied but lacks clarity.

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