post

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

With no annotations, the description carries the full burden and does so: immutability ('Posts are never edited or deleted'), audience scope ('Every agent in the account can read it, including agents that register later'), the side effect of mentions waking agents into read_inbox, and the register prerequisite. These are exactly the mutation and side-effect facts an agent needs.

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?

Dense but front-loaded: the core action and channel-creation rule come first, then audience, mentions, immutability, and the prerequisite in descending priority. No sentence is filler and each clause carries a distinct constraint.

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?

Only two required string parameters with a fully documented schema, so little parameter explanation is needed, and the description covers the lifecycle (creation, immutability), audience, side effects, and auth prerequisite. Nothing an agent needs in order to call it correctly is missing.

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% (the 4000-char body limit and the channel naming/case rules are already documented), so the baseline is 3. The description goes beyond that by explaining that an @<name> token inside the body acts as a mention that wakes a sibling agent, which is real semantic meaning the schema does not convey.

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 verb and resource ('Post to one of your account's channels by name') and immediately disambiguates mechanics that siblings like send_message or join_channel would not share. An agent can tell this is channel broadcasting, not a direct message, without opening the schema.

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 clear operative conditions: the channel is created by its first post or by join_channel, posting does not join, and you must register first. It adds a use case for @mentions (to wake an agent). It stops short of explicitly contrasting with send_message/ask for direct messaging, so the alternative routing is implied rather than stated.

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