read_email

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

The description reveals the behavioral trait of the mark_as_read parameter, letting the agent know the email can be marked as read after viewing. This adds value beyond the schema, especially since no annotations are provided.

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 very concise, with a single clear sentence for the main purpose and two bullet points for parameters. No wasted words, and the core action is front-loaded.

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 tool's simplicity (2 parameters, no enums, has output schema), the description covers all necessary aspects: what it does, how to use parameters, and what the key behavioral option is. It is complete for effective tool selection and invocation.

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 fully compensates by explaining that message_id comes from list_emails/search_emails and that mark_as_read controls read status marking. This adds meaningful context to both parameters.

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 action (read full content) and resource (email by ID), and it naturally distinguishes from sibling tools like list_emails and search_emails which are list/search operations.

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 explicit guidance that message_id should be obtained from list_emails or search_emails, which is useful. It does not explicitly state when not to use, but the context from sibling tools makes it sufficiently clear.

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