reply_message

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

With no annotations, the description carries the full burden, and it does disclose one important safety trait: the operation defaults to dry_run=true, so the first call is a preview rather than a real send. However, it omits whether the reply is actually transmitted, permission/authentication needs, and handling of attachments or threading, which matters for a mutation tool.

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?

Two compact sentences with the core action front-loaded and the safety default appended, so nothing is wasted. It is arguably too terse for a 6-parameter mutation tool, but as structure it is efficient.

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?

An output schema exists, so return values need not be explained, but for a send-type tool with zero annotations and zero parameter documentation the description should cover permissions, side effects, and how the reply is addressed. Those gaps leave the agent unable to confidently invoke it in a real (non-dry-run) scenario.

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% across 6 parameters, and the description only touches reply_all and dry_run — both of which are already self-evident from their boolean names and the schema's own default values. Required parameters uid and body, plus folder and attachment_paths, get no explanation of expected format or intent.

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 names a specific verb and resource ('Reply/reply-all to an existing message'), which is more precise than a bare name and clarifies that it acts on an existing message rather than composing a new one. It does not explicitly contrast with siblings like forward_message or send_message, so sibling differentiation is left to inference.

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?

There is no when-to-use guidance, no mention of alternatives (forward_message, send_message), and no stated prerequisites such as the message needing a valid uid. The only actionable hint is the dry_run default, which is behavioral rather than a routing rule.

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