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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, and the description does not contradict them. It adds genuine operational context beyond the annotations: no web fallback for custom schemes, unsafe and internal schemes blocked, iOS version/build floors (1.13.4 build 2, 1.16.0), and that the result carries a notification_id usable with replace_push_notification. Some of this restates schema property text, which keeps it from a 5.

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 sentence front-loads the purpose well, but the body is a long undifferentiated block and several paragraphs (redirection URL rules, media/actions mutual exclusion, icon rendering) substantially repeat the corresponding schema property descriptions. The action example block earns its place; the redundancy with structured fields does not.

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 14-parameter tool with nested objects, one enum, and a 100%-covered schema, the description covers the hard parts: platform requirements, blocked schemes, option mutual exclusions, and the notification_id handoff to replace_push_notification. An output schema exists, so return values need not be explained, and nothing needed for a correct call 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%, so 3 is the baseline; the description earns a point by supplying concrete, correctly-shaped action examples (open_url with a GitHub URL, a shortcuts:// scheme, and a webhook with method and JSON body) that show how the untyped 'actions' array items should be constructed. That is meaningfully more than the schema conveys, though the remaining 13 parameters get nothing extra.

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 resource ('Send an ActivitySmith Push Notification to this account') plus the optional targeting scope ('Optionally target channel slugs'). It also names the sibling that continues the workflow ('Pass it to replace_push_notification to update this notification later'), so an agent can distinguish it from replace_push_notification and list_push_notifications without opening a 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?

Gives conditional guidance on option selection: 'use time-sensitive only for things the user must see now', 'media can be combined with redirection, but media cannot be combined with actions', and routes follow-up updates to replace_push_notification. It does not state when to prefer this tool over siblings like list_push_notifications or get_push_notification, but for a creation tool the operative 'when' is largely covered.

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