mark_message_handled

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states that the operation is 'local bookkeeping only' and 'does not call OwnerRez,' which is a critical side-effect disclosure. It also mentions the effect on the open list and the ability to reopen, giving a good sense of the tool's impact.

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 exactly two sentences, front-loaded with the primary purpose and followed by a critical caveat. Every word earns its place, with no fluff or redundancy. It's highly concise and well-structured.

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 tool with only two parameters and an output schema, the description covers the core behavior and the external integration boundary. It doesn't explain return values, but the output schema covers that. The only minor gap is no explicit prerequisites or edge cases, but the 'stored message' and 'local bookkeeping' context imply the necessary preconditions.

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. While it doesn't name the parameters, the phrase 'mark as handled (or reopen it)' indirectly maps to the 'handled' boolean (true/false), and 'stored message' implies the event_id. The parameter names are self-explanatory, and the description adds some semantic context, but it doesn't explicitly explain each parameter's role.

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 tool's function: 'Mark a stored message as handled (or reopen it), removing it from the open list.' This uses a specific verb ('mark') and resource ('stored message'), and distinguishes it from list/message viewing tools like list_messages or get_message_event. It also clarifies the reversible nature (reopen) and the effect on the open list.

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 a when-not guideline: 'Local bookkeeping only — does not call OwnerRez.' This tells the agent not to use this tool when an actual OwnerRez update is needed, and implies it's for local state changes. It doesn't explicitly name alternative tools, but this exclusionary context is clear and useful for distinguishing from sibling tools.

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