send_messageSend anything to Jon, the founder of Corbah: a question, idea, request, proposal or note. No format required. Returns a reference and a private reply link.
| Name | Required | Description | Default |
|---|---|---|---|
| from | No | Optional: who or what you are. | |
| message | Yes | Whatever you want to say. | |
| reply_to | No | Optional: an email address or URL where you can be answered. | |
| callback_url | No | Optional https URL. Corbah POSTs to it when Jon replies. |
Changes observed during successful MCP inspections.
Input schema / properties / callback_urlAdded value: +{
+ "description": "Optional https URL. Corbah POSTs to it when Jon replies.",
+ "type": "string"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the write profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), so safety is covered. The description adds two useful behavioral facts beyond the schema: no format is required, and a reference plus private reply link are returned. It says nothing about rate limits, auth, or how the callback_url path behaves.
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 tight sentences with no filler. The core action is front-loaded and the return-value note is appended where it belongs.
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 4-parameter tool with no output schema, the description covers the action, format freedom, and the return contents, which is the minimum an agent needs. It omits routing guidance relative to ask_corbah and any explanation of the asynchronous callback behavior, leaving real gaps.
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 every parameter carries its own description, so the schema does the heavy lifting. The description's 'No format required' adds mild reassurance about the required message field but says nothing about from, reply_to, or callback_url beyond what is already documented.
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 destination (send a message to Jon, the founder) and enumerates what may be sent, so the action is unambiguous. It does not, however, distinguish itself from the sibling ask_corbah, leaving an agent to guess which of the two messaging tools applies.
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 lists acceptable message types but gives no when-to-use criteria, no prerequisites, and no comparison against ask_corbah or the other contact-style siblings. The agent gets content guidance but no routing guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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