add_channel_member

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

No annotations are provided, so the description carries the full burden. It discloses the authorization requirement (channel creator or mesh admin only) and a precondition on the target user's state, which are non-obvious behavioral traits. It could go further on idempotency or what happens on re-add, but the core constraints are well covered.

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 sentences, front-loaded with the action and qualification, with no wasted words. The authorization note is tucked into the parenthetical efficiently.

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 two-parameter mutation with an output schema, the description supplies the authorization rule, the accepted formats for the user identifier, and the mesh-membership precondition. An agent has what it needs to call this correctly.

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 0%, so the description must compensate. It does: 'user' is explained as a username, display name, or UUID, and the channel is implicitly the target channel. This adds real meaning beyond the bare string-typed schema.

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 ('Add a mesh member to a channel') and clearly distinguishes from sibling remove_channel_member and list_channel_members. The parenthetical rule reference (§88a) further disambiguates the operation.

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 when-to-use context: channel creator or mesh admin only, and the user must already be an accepted mesh member. It does not explicitly name alternatives, but the constraints effectively tell the agent when this tool will and won't work.

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