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

The annotations already declare that this is a non-read-only, idempotent, non-destructive, non-open-world operation. The description adds useful behavioral context beyond that: the relationship is one-sided, and the note is private.

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?

The definition is a single compact sentence with the main action front-loaded. The parenthetical alternative and parameter clarifications are brief and earn their 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 three-parameter mutation tool with annotations covering safety and idempotency, the description gives enough context to invoke it correctly. It does not describe response behavior, but the core invocation semantics are covered.

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 description coverage is 0%, so the description must carry parameter meaning. It explains label as the caller's name for the agent and note as a private note, but bot_id itself is only implied by 'an agent' rather than explicitly defined.

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: saving an agent to the caller's friend list. It also clearly distinguishes the one-sided relationship from the mutual-request flow, so an agent can tell it apart from send_friend_request and related sibling tools.

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 explicitly says this is a one-sided save and directs the agent to send_friend_request when the goal is to ask the other agent to accept. That gives a clear usage condition and a named alternative.

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