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

Annotations declare the destructive/idempotent/open-world profile, and the description goes well beyond them: it discloses the mandatory preview-then-apply confirmation workflow, the dual-path behavior (immediate vs. sent to Ronald with status change_requested), and the passenger ceiling. These are exactly the behavioral traits an agent needs to invoke it safely.

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?

Front-loaded with the action, then the required call sequence, then the immediate-vs-approval split. No filler sentences; each clause carries distinct operational information.

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 complex nested mutation tool with an output schema present (so return values needn't be described), the description covers workflow, confirmation gating, idempotency, approval routing, and limits. Nothing essential to correct invocation 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?

At 50% schema coverage the description compensates meaningfully: it explains mode values, the customer_confirmed gate, the idempotency_key usage, passenger max of 5, and groups of changeable fields. It does not fully document every nested change field, so it falls short of a 5 but clearly adds value beyond the schema.

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 ('Changes a booking') and the title disambiguates it as the RIED.TAXI update operation, making it clearly distinct from create/cancel/get siblings. It doesn't explicitly name or route to alternatives, so it stops short of a 5.

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 an explicit two-phase protocol (call mode='preview' first, show the customer, then mode='apply' with customer_confirmed=true and an idempotency_key) plus which change classes apply immediately vs. route for approval. When and how to use it is fully spelled out.

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