message_reply

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

With no annotations, the description must carry the full burden of behavioral disclosure. It only states 'send as a reply' without explaining whether messageId is mandatory, what the response contains, what side effects occur, or how replying differs from sending new messages.

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 short sentence, so it is concise but largely restates the tool name. It lacks structure but is not overly verbose, earning a middle score for brevity without added substance.

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 6 parameters, nested objects, and no output schema, the description is severely under-specified. It does not explain behavior, return values, prerequisites, or error conditions, making it inadequate for a complex messaging tool without relying heavily on schema and sibling context.

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 100%, so the baseline is 3. The description does not add semantic nuance beyond what the schema already provides; it only frames the operation as a reply, which is minimal extra value.

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 'Send a message as a reply' clearly identifies the action (send) and resource (a message as a reply), distinguishing it from sending a new message (client_sendMessage) or forwarding (message_forward). However, it could be more explicit about targeting a specific message via messageId.

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?

No guidance is provided on when to use this tool versus alternatives like client_sendMessage or message_forward. There is no mention of prerequisite context such as requiring chatId and messageId.

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