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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=true, so the safety profile is covered. The description adds almost no behavioral context beyond the name — it does not say whether disabling wipes settings, whether delivery_time is persisted when emails are off, or what the response confirms. 'Daily' is the only new fact, and it largely restates the title.

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?

A single front-loaded sentence with no filler or redundancy. It is efficient, though its brevity is partly a symptom of the thin content rather than evidence of sharp editing.

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 tool with no output schema, the description plus full schema coverage and annotations is enough to invoke it correctly. It is still incomplete on the effect side: nothing explains the relationship between `enabled=false` and the optional `delivery_time`, which is the one ambiguity an agent could hit.

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%, including an explicit note that `enabled` is true-to-enable/false-to-disable and the allowed delivery_time values. The description adds nothing beyond the schema, so the 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 pair (enable/disable) and a specific resource (daily email notifications), with scope made explicit as 'your leads and updates'. It does not name a sibling or disambiguate against the other mutating tools (add_to_watchlist, update_targeting_preferences), but the function is unmistakable.

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?

The description gives no when-to-use context, no prerequisites, and no alternatives. It never says whether toggling off preserves preferences, or whether this is the only route to change notification cadence. An agent can only infer the trigger condition from the tool name.

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