get_unread_messages

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

With no annotations provided, the description carries the behavioral burden. It does add a useful auth prerequisite by mentioning the privatemessages scope, but it does not disclose ordering, pagination behavior, side effects on unread state, or rate limits. For a simple read operation this is adequate but minimal.

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 compact and front-loaded with the core purpose, followed by a brief Args block. There is no filler or redundant information, and each sentence contributes something useful.

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 two-parameter read tool with an output schema, the description covers the core action, required scope, and main parameter constraints. It does not need to describe return values since an output schema exists. The main gap is the missing distinction from get_inbox_messages, but the description is otherwise close to complete for correct 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?

Schema description coverage is 0%, so the description must compensate. It does add value by specifying that limit accepts 1-100 with a default of 100 and that access_token is optional. However, access_token's actual role, source, or relationship to stored credentials is not explained, leaving only partial compensation.

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 ('Get user's unread messages') and resource, which makes its purpose evident. It is distinct from sibling tools like get_inbox_messages and get_sent_messages by focusing on unread messages, though it does not explicitly call out those alternatives.

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?

There is no guidance on when to use this tool versus alternatives such as get_inbox_messages or get_sent_messages. The only contextual hint is 'requires privatemessages scope,' but the description does not explain when this tool is preferable or what it excludes.

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