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

Annotations already cover the safety profile (readOnly, non-destructive, openWorld). The description adds valuable behavioral context beyond that: pre-filled dates/product, price inclusive of fees and VAT, cancellation terms included, and the 'unavailable' price_status edge case.

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 core promise (firm price + checkout link) before usage guidance and return details. Dense but every sentence carries information; slightly long but not padded.

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?

With no output schema, the description does the work of describing returns (onepass/multipass/subscription products, totals with fees/VAT, cancellation terms, price_status). An agent has enough to call and interpret it, though the shape of the returned object is only loosely sketched.

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%, so all five parameters are already documented in the schema. The description adds only light context (dates and product pre-filled) and no format or constraint details beyond it, so the baseline 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: returns the firm final price(s) and a checkout_url for a parking/date range. Clearly distinguishes itself from `search` (browsing) and `get_parking` (static details) by emphasizing firmness and bookability.

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?

States when to use it: 'once the user has chosen a parking (typically from `search`)' to confirm price or hand over a booking link. This implicitly routes agents away from search, though it doesn't state an explicit when-not condition.

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