ebay_reply_to_message

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

With no annotations provided, the description carries the full burden. It states the action but omits behavioral details such as whether the reply is immediately visible to the buyer, any character limits, or if the caller must be the seller. It only says 'Reply' but gives no confirmation of 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 a single, direct sentence that immediately conveys the core action and context. Every word is meaningful with no unnecessary elaboration.

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 (no output schema, no nested objects, 2 required string parameters), the description is nearly complete. It lacks explicit mention that the reply is sent to the buyer, but the purpose is clear enough for an agent to use correctly in common scenarios.

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 coverage is 100% and both parameters have descriptions that clearly define their purpose. The description adds minimal new meaning beyond 'existing conversation thread', which is predictable from the tool name. Baseline score of 3 is appropriate.

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 ('Reply to a buyer message') and specifies the context ('in an existing conversation thread'), distinguishing it from siblings like 'ebay_send_message' (which likely starts a new conversation) and read-only tools like 'ebay_get_message'.

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 replying in existing conversations but does not explicitly state when to use this tool versus alternatives (e.g., starting a new message or reading messages). No prerequisites or when-not-to-use guidance is provided.

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