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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds genuinely useful behavior: that it requires a token and that the response covers seat occupants, seats remaining, exchange cost, and a share link. That compensates for the absence of an output schema; it stops short of noting failure modes or whether costs are estimates.

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?

A single sentence with the most valuable information (what fills the seats, seats left, cost, share link) front-loaded, plus a short parenthetical for the token requirement. Nothing wasted, though the parenthetical reads as an afterthought.

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 single-parameter read tool with no output schema, the description does the necessary work by enumerating the return contents and flagging the token requirement. It could be slightly stronger by clarifying how this differs from the other status/list siblings, but nothing essential to correct invocation 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% with a concrete example (com.example.app), so the schema already carries the parameter meaning. The description only reinforces the scope ('one of the user's apps'), which is marginal added value over the schema — the baseline 3 applies.

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 names a specific resource (the 12 seats of one of the user's apps) and enumerates what it returns: seat occupants, remaining seats, exchange cost, and share link. That is far more concrete than a bare 'status' restatement, though it doesn't explicitly distinguish itself from siblings like swap_circle_status or my_swap_circle.

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?

There is no statement of when to use this versus swap_circle_status, my_swap_circle, or my_tests; the agent must infer from the 'friends, swap circle, exchange testers' parenthetical that this covers a single package's seat view. It does hint that a token is required, but that is auth context rather than usage routing.

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