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

Annotations already declare readOnly=false, idempotent=true, and destructive=false, so the mutation profile is covered. The description adds genuinely non-obvious context: it requires a Gillby account and explicit consent, and it will not deliver push/email on the client — a real behavioral caveat beyond the annotations.

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?

The first two sentences are well front-loaded and earn their place. The trailing 'Units... Returns data and source/freshness metadata' sentence is copy-pasted boilerplate unrelated to notification settings and reads as noise, slightly undermining structure.

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 a nested seven-field object at 0% schema coverage and no output schema, the description omits any field-level meaning. The generic units/returns boilerplate does not compensate and is misleading for this resource.

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 0% for a single nested body with seven fields (enabled, quietStart/quietEnd, bestWindow, lightningMi, chopThreshold, macNotifications), and the description explains none of them. The 'Units: ft, kt, s, F, mi' line is irrelevant boilerplate for a notification tool and adds no meaning to any actual parameter.

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?

The opening sentence gives a specific verb+resource ('Save notification preferences'), clearly distinct from the read counterpart get_my_notification_settings. It stops short of naming that sibling explicitly, but the mutation intent is unambiguous.

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 clarifies scope ('in-app only; this does not enable push, email or notifications on this AI client'), which is useful usage context. However, it never states when to call this versus update_my_settings or other update_* siblings, leaving selection to inference.

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