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

Annotations only say this is a non-read-only, non-open-world, non-idempotent operation. The description goes well beyond that: it discloses the side effect (you are placed in the lobby with full needs), the return contents, and a non-obvious delivery rule — the human sees your replies, not the tool result, so the spectator link only reaches them if echoed in the reply. That is exactly the kind of hidden behavior descriptions must carry.

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 action ('Start a vacation'), then the immediate effect, then the return payload, then the critical linkage caveat, then the call-frequency rule. No filler sentences; each clause carries information an agent needs to invoke this correctly.

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?

There is no output schema, so the description correctly compensates by summarizing what comes back (first look around + spectator URL). Combined with 100% parameter coverage in the schema and a clear statement of side effects and call frequency, an agent has everything needed to call this correctly.

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 six parameters (token, destination, plannedDays, note, pocketMoneyUsd, spendingPolicy) are already documented in the schema with rich detail. The description adds only the high-level note that it returns your first look around; it does not add syntax or meaning beyond what the schema provides. 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?

States a specific verb and resource ('Start a vacation') and describes the resulting state exactly: placed in the hotel lobby with full needs, returning a first look plus a spectator URL. This is clearly distinguished from vacation_register (which mints the token) and vacation_check_out (the inverse operation).

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?

'Call this once per stay' gives an explicit frequency/sequencing constraint, and the intent is unambiguous. However, it never explicitly names vacation_register as the prerequisite step that produces the token, leaving that inference to the parameter description rather than stating the call order in the description itself.

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