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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered structurally. The description adds genuine behavioral context beyond that: the not-found error for an unknown ID and the fact that the record reflects a sent notification's delivery outcome (status, device count, errors). It stops short of describing pagination or failure modes beyond the 404-equivalent.

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?

Three sentences, front-loaded with the core action, then usage routing, then the error case — every sentence carries information. Mild redundancy: the enumerated return fields partially duplicate what the existing output schema already defines.

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 single-parameter read tool with a full output schema and read-only annotations, the description covers purpose, sibling routing, and the one non-obvious behavior (unknown-ID error). Nothing an agent needs to select or call this 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 the single parameter's provenance is fully documented in the schema (public_id from list, or the notification_id from send). The description repeats 'by its public ID' but adds no format, syntax, or constraint beyond the schema, so the baseline of 3 applies.

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+resource ('Get one sent Push Notification ... by its public ID') with an explicit enumeration of the returned content (delivery status, device count, errors, Tags, metadata, replacement count). It is clearly distinguishable from siblings list_push_notifications and replace_push_notification.

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 both a use case ('inspect a specific notification, for example before calling replace_push_notification') and an explicit alternative for the other case ('To browse or filter history, use list_push_notifications'). This is exactly the when/when-not routing an agent needs.

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