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

Annotations already flag destructiveHint=true, but the description supplies context annotations cannot express: what is destroyed is only future posting (existing posts persist, including scheduled ones, which need a separate cancel_post call) and the required delete scope. This is exactly the kind of side-effect and auth detail the highest bar asks for.

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 tight sentences, front-loading the core action and its effect before the alternative-tool routing and the scope requirement. No filler or restatement of the tool name.

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 destructive, single-required-param tool with no output schema, the description covers effect, persistence of past/scheduled posts, the cancellation path, the sibling alternative, and the auth scope — nothing an agent needs before calling it 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 description coverage is 100%, so both 'id' and the optional 'sourceUrl' are fully documented in the schema, and the description adds nothing about either. Baseline 3 is appropriate when the schema does all the parameter work.

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 ('Stops following a feed') and immediately defines the observable consequence ('no new post is made from its articles'), which distinguishes it from update_feed and cancel_post by name. An agent can pick this tool without opening any other 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?

Explicitly routes to alternatives with conditions: cancel_post for already-scheduled posts, update_feed for account/approval changes only. It also states a prerequisite (delete scope), so both when-to-use and when-not-to-use are covered.

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