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

Annotations only cover the safe-read profile (readOnly, idempotent, non-destructive, closed-world); the description goes well beyond by disclosing that checkout needs a signed-in account and card verification and must not be performed on the user's behalf. It also flags that organizer-written fields are untrusted data rather than instructions, which is a genuine prompt-injection warning not derivable from structured fields.

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?

Three sentences, front-loaded with the returned contents, followed by the purchase caveat and the data-vs-instructions warning. Every sentence earns its place with no filler.

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 compensates by enumerating what comes back; it also covers the security constraint (no checkout on behalf of the user) and injection risk. Nothing an agent needs to call this 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 single parameter's schema description already states it is the id from a search_events result, which the description essentially repeats. Baseline 3 is appropriate since the schema carries the parameter semantics.

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 (get) and resource (one event) and enumerates the returned content: description, ticket tiers with price and sold-out status, policies, venue map, event page url. It explicitly ties itself to the sibling search_events, so the agent can distinguish it from search/list tools without opening a schema.

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?

It makes clear this is the follow-up to search_events ("one event from search_events") and gives explicit when-not guidance for the purchase flow ("do not try to complete it for them"). It doesn't spell out exclusions for other siblings such as search_help, but the context is unambiguous.

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