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

Annotations already establish read-only and non-destructive behavior. The description adds useful non-obvious behavior: the handle may be expired/not found, the result should be reused while valid, and polling should not be initiated. It doesn’t cover every edge like rate limits, but the annotation coverage is already strong.

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?

Three sentences with no filler: purpose, accepted input, probable outcome, usage caution, and alternative. The most important discriminators appear first, and every clause adds value.

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 one-parameter read-only checker, this description is complete: it covers purpose, parameter format, return intent, list behavior, and the alternative tool. Output schema is already available, so the return type is documented elsewhere; nothing an agent needs to call the tool 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?

With schema description coverage at 0%, the description fully compensates by explaining the accepted handle formats: ci_*, Meta connect_id, or Meta connect_id or fbconn_live_*. This gives the agent concrete selection criteria and is especially important for this one required parameter.

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 ('check'), resource ('existing authorization handle'), and expected outcomes ('status/channel or not_found_or_expired'). It also differentiates this tool from the setup path by naming setup_check_channel_connect, so an agent can pick it correctly without opening sibling schemas.

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 timing guidance ('after the user finishes'), tells the agent to reuse the link while valid, and forbids automatic polling. It explicitly directs setup connect_id cases to a sibling tool, making the choice between this and setup_check_channel_connect unambiguous.

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