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

Beyond annotations, it discloses the plan_required error contract, the upgrade_url in message/user_message, the grandfathered exception (badge off before 2026-10-25 is kept), the return payload, and clarifies it writes only the setting and contacts no outside system. This is rich behavioral context that annotations alone (readOnly=false, idempotent=true) cannot convey.

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?

Front-loads the core distinction (Free shows badge, Hobby/Pro never) before the mechanics, so a reader gets the gist immediately. It is a single dense block with minor redundancy ('show true shows it again' echoed) and a slightly run-on error sentence, but little is wasted.

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 mutation tool with no output schema, the description still specifies the return value (stored setting and whether shown), the error path, and the no-outside-contact guarantee. Nothing an agent needs to invoke it 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?

Schema description coverage is 100% and each property already documents its meaning and plan behavior, so the schema carries the load. The description's extra param detail (slug scope, token optionality with Authorization header) largely restates the schema, so baseline 3 is appropriate.

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+resource ('set_the_badge'-style operation on the published-with badge) and distinguishes behavior by plan tier. An agent can immediately tell this controls badge visibility on deed.page, unlike any sibling tool.

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 explains scoping: 'With slug, the setting applies to that site; without slug, it applies to every site of the token.' It also spells out the plan-dependent outcomes (Free refused, Hobby/Pro no-op) with a concrete do-not-retry directive on plan_required, leaving nothing to inference.

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