mark_messages_read

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

Annotations already indicate the tool is not read-only and not destructive. The description adds behavioral details beyond annotations: batch limit of 25, comma-separated short ID format, and the toggle between read and unread via the 'read' parameter. No contradiction with annotations.

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 exceptionally concise: a one-sentence purpose followed by a two-line args spec. Every word earns its place, no fluff, and the key info 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?

For a simple state-change tool, the description covers purpose, parameters, constraints (batch size, ID format), and aligns with annotations for safety. The output schema handles return values, so no extra explanation is needed here.

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 carries full responsibility for parameter meanings. It clearly explains message_ids (short IDs, comma-separated, example, limit) and read (True/False semantics), fully compensating for the schema's lack of descriptions.

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 verb 'mark' and resource 'messages' with the state change (read/unread). It distinguishes from siblings like move_messages and archive_messages by specifying the state mutation, and from mark_read_by_search by focusing on specific message IDs.

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 usage for specific message IDs but provides no explicit guidance on when to choose this tool over alternatives like mark_read_by_search. It lacks a when-to-use or exclusion statement, though the parameter semantics make the context clear.

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