List Proton messages

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the bar is lower. The description adds concrete behavioral value by guaranteeing the operation does not mark messages as read and that only metadata is listed. It does not cover auth or rate limits, but the annotations cover the main safety profile.

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 efficient sentence with no wasted words. The main purpose and key side-effect guarantee are 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?

For a simple list operation with optional, reasonably self-explanatory parameters and a read-only annotation, the description plus schema is mostly adequate. However, missing sibling routing and any parameter clarification leave moderate gaps for an agent deciding how to use the tool 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% and the description provides no parameter information. limit, folder, and unread_only must be inferred solely from names, types, and defaults; the description adds no meaning beyond the input schema.

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 and resource ('List message metadata') and explicitly distinguishes itself from read_message by noting it does not mark messages as read. However, it does not name or differentiate from search_messages, so sibling differentiation is incomplete.

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 guidance on when to use this tool versus search_messages, read_message, or other siblings. The phrase 'without marking messages as read' is a behavioral note, not a routing rule or explicit alternative.

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