delta_messages

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

There are no annotations, so the description carries full behavioral burden. It only reveals that the first call omits delta_token and start_date_time is ISO 8601; it does not disclose what 'message changes' includes, token lifecycle, pagination, or data scope.

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 short and front-loaded with the core operation. Every sentence adds some information, though the terse phrasing leaves important details unstated.

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?

With no annotations and no output schema, the description is too sparse for full invocation confidence. It omits the message scope, return format, and how delta synchronization continues after the first call.

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 adds some meaning for delta_token and start_date_time, but it fails to explain how the two parameters interact or what delta_token represents on subsequent calls.

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 states a specific operation ('Get message changes') and resource ('messages'), which is reasonably clear. However, it does not distinguish this from sibling tools like list_messages or delta_query, leaving some ambiguity about the exact scope.

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?

It provides useful first-call guidance: omit delta_token, and start_date_time must be ISO 8601. But it does not explain when to use this tool instead of alternatives such as list_messages or search_messages, nor how subsequent calls should be structured.

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