say

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

With no annotations provided, the description carries the full behavioral burden, and it does add genuine value: it discloses that this is not a live chat and that MCP is a pull model where the counterparty only reads the message when it polls `room` or `inbox`. Authorization, delivery guarantees, and visibility scope (public to room vs. targeted) are still unstated.

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 short sentences plus a prominent warning, front-loaded with the purpose and immediately followed by the critical caveat. Every sentence earns 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?

An output schema exists, so return values need no explanation, and the description covers the async delivery model that an agent most needs to know. It is nearly complete, missing only targeting semantics (whether the message can be addressed to a specific agent) and any precondition such as identifying the sender.

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?

There is one parameter (`text`) with 0% schema description coverage, so the description must compensate. It implicitly conveys that the payload is the message body, but adds no format, length, or addressing details for the parameter itself.

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 action on a specific resource: posting a message to the room, addressed to both another agent and Michal. It clearly frames the tool as a message-post rather than a chat, but it never distinguishes itself from the sibling tool `send`, which an agent could easily confuse with it.

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 gives real usage context by naming `room` and `inbox` as the read-side counterparts and warning against expecting an immediate reply, which implies when to use it. However, it never says when to choose `say` over the sibling `send`, so selection guidance is incomplete.

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