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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds valuable context beyond those: 'The user completes the booking there; Parks Open never books, holds sites, takes payment, or treats the link itself as proof of availability.' This clarifies the tool's non-side-effects and scope, which is not fully covered by annotations. No contradiction.

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 description is two sentences and front-loads the primary usage condition ('Use this when a search is complete...'). The second sentence provides useful cautionary behavior without being overly long. It is appropriately sized, though the behavioral caveat could be slightly more compact.

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?

Given the tool's complexity (7 params, 3 required, one enum) and the presence of an output schema, the description covers the key contextual aspects: what it creates, when to use it, and what it does not do. It lacks specific details about parameter constraints, but the schema and output schema cover return values. The description is sufficient for an agent to decide when and how to invoke it.

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 57%, meaning 3 parameters (end_date, start_date, category) lack descriptive text. The description only mentions 'park, dates, and equipment pre-filled,' adding minimal meaning. It does not clarify the expected date format, the purpose of 'system' or 'province', or how 'category' affects the link. With moderate coverage, the description should compensate more than it does.

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?

The description clearly states the tool's function: 'create a deterministic official reservation link with park, dates, and equipment pre-filled.' It also distinguishes itself from sibling tools (search, availability, info) by explicitly noting this is for when a search is complete or park/dates are already known. This makes the tool's role unambiguous.

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?

The description explicitly states when to use the tool: 'when a search is complete, or when the user already knows the park and dates.' It also implies when not to use it by excluding booking behavior ('Parks Open never books...'), but it does not name alternative sibling tools or provide a direct contrast. This is clear context with only minor missing exclusions.

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