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

Annotations already declare readOnly=false, idempotent=true, openWorld=true and destructiveHint=true, so the safety profile is largely covered. The description adds the plan-gating requirement, which is valuable, but says nothing about the effect of turning it off (e.g. stopping delivery) that would justify the destructive hint.

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?

Two short sentences, action first and constraint second, with zero filler. Everything is front-loaded and every clause carries information.

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 toggle with no output schema and annotations that already convey idempotency and destructiveness, the description covers purpose, scope, and plan eligibility. Nothing essential to calling 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 coverage is 100%, and the schema fully documents 'enabled' and 'website_id', including the 'omit to use primary website' fallback. The description's 'for one website' adds only a slight scoping hint, 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?

Specific verb (turn on/off) plus resource (daily email summary of chats) and scope (one website). The read/write distinction from the sibling get_daily_report is inferable, but the description never explicitly contrasts them, so it stops short of full sibling differentiation.

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 supplies a useful prerequisite ('Needs the Standard plan or higher'), which is genuine when-to-use context. However, it gives no guidance on when to use set_daily_report versus get_daily_report, nor any exclusions or side-effect warnings that would steer selection.

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