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

Annotations already declare the write, idempotent, non-destructive profile, so the description's job is to add context beyond that — and it does: the effect is deferred to the next production deploy, the operation can be refused on plan grounds with an upgrade message, and config:write is required. That is exactly the kind of timing, authorization, and failure-mode detail annotations cannot carry.

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?

Four short sentences, front-loaded with the action, then the true/false semantics, then timing, then the constraint and precondition. Every sentence carries distinct information; nothing is restated or padded.

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 no output schema, the description covers effect, timing, authorization, and the failure case (including that the refusal message states what to buy). There is no meaningful gap an agent would need filled before calling it.

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%, so a 3 is the baseline, but the description earns a point by supplying consequences the schema does not: badge true causes SHIP to refuse a production deploy whose pages lack the badge. The schema's own description is terse ('require the badge on every page') and the description supplies the deploy-level enforcement meaning.

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 a precisely scoped resource: 'Set the "Built with SHIP" badge rule of a hosted site.' This is clearly narrower than update_project or update_scheduled_task in the sibling list, and the scope is unambiguous without opening the 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?

Explains what each setting value means operationally (true = deploys refused without the badge, false = site config decides) and when the change takes effect (next production deploy). It also names a precondition — the config:write capability — and a blocked path (plans that keep the badge on). It does not name a sibling alternative, but for a two-parameter, single-purpose tool there is no plausible alternative to route to.

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