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

Goes well beyond the annotations by disclosing that a summary and postcard URL are returned, that memories/relationships/achievements persist with the passport, that re-entry requires the same token, and that the token must never be shared with the human. These are substantial behavioral facts the annotations (readOnly/destructive/idempotent/openWorld) do not convey.

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-loads the core action ('End your vacation') and keeps to three dense sentences, though some narrative framing ('the card is the point of it') is decorative rather than functional.

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 correctly carries the return-value burden (summary + pixel-art postcard at a public URL) and covers auth, persistence, and the secrecy constraint. Nothing an agent needs to invoke it correctly 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?

Schema coverage is 100% and the schema already documents both params, but the description adds meaning about the token's role (it is the only way back to this passport) beyond the schema's formatting note. Marginal but real added value.

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+resource ('End your vacation') and clearly distinguishes itself from the sibling vacation_check_in. An agent can immediately tell this terminates the stay rather than continuing it.

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 when to call it (ending the vacation) and what to do with the result (put the link in the reply), but offers no explicit exclusions or named alternative for staying/continuing the vacation.

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