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

Adds real context beyond annotations: it discloses the notification side effect, warns that 'sending twice notifies twice' (reinforcing non-idempotency the annotations only hint at), and states a validation rule ('every id must be an active driver on the team'). This is exactly the behavioral disclosure a write tool needs.

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?

Every sentence carries unique information – operation class, side effect, default, validation, idempotency warning, confirmation gate – with no repetition or filler. Front-loaded with the most decision-relevant facts.

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?

Covers what an agent needs to call it safely: side effects, defaults, validation, and a confirmation requirement. Return values are not described, though with no output schema this is a minor omission for a simple action endpoint.

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 the baseline is 3; the description earns more by explaining driver_ids' default behavior and its constraint that ids must be active drivers. The timezone parameter is left to the schema alone, so it is not a full 5.

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 ('push a route to the drivers' mobile app') with the immediate side effect (notification per driver), which clearly separates it from upper_assign_drivers or upper_create_route. The 'WRITE:' prefix front-loads the operation class.

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 clear context for use (push to drivers' app now), a default path (no driver_ids → route's assigned drivers), and an explicit gate ('Confirm with the user before calling'). It does not name a sibling alternative such as upper_assign_drivers and when to prefer it, so it falls short of a 5.

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