Add a reply to a feedback thread without changing its status, so you can post progress notes, questions, or a preview URL while keeping the workflow stage intact.
Reply on a thread without changing its status — progress notes, questions, or the preview URL when it goes live. The status is left exactly as it was.
| Name | Required | Description | Default |
|---|---|---|---|
| message | Yes | Markdown. Say something useful; a person reads this. | |
| thread_id | Yes |
Changes observed during successful MCP inspections.
v0.14.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full disclosure burden. It does disclose the key non-side-effect (status unchanged), but says nothing about notifications recipients receive, message ordering/threading, editability, or permissions required. Adequate on the one trait it covers, silent on the rest.
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?
Front-loaded and short, but the two sentences are partially redundant — the second restates the non-mutation of status already asserted in the first. One clause of the text is not earning its place.
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 two-parameter append tool with no output schema and no annotations, the description covers the essential behavioral promise (non-destructive to status) and intended content. Missing details about downstream notification or ordering are minor at this complexity level.
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 50%: 'message' has a schema description (Markdown) while 'thread_id' has none. The description adds useful content guidance for the message body but no format or identifier semantics for thread_id, so it only marginally compensates for the coverage gap.
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?
States a specific verb and resource (reply/add a message on a thread) and immediately scopes it against the status-changing siblings by declaring it does not alter status. The examples of message content (progress notes, questions, preview URL) make the intended action concrete.
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?
Gives clear usage context via content examples and implicitly routes status changes to siblings (update_status, mark_thread_addressed) by stating the status is left untouched. It never names those alternatives explicitly, so the routing is inferable rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.