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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description is free to add domain behavior. It does: the reserve-mode eligibility gate and the exact contents of the response (names, prices, sale status, remaining count, pricing options), which is what an agent needs before calling. No mention of error behavior when the mode is not "reserve", which keeps it off a 5.

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?

Four short sentences, front-loaded with the core purpose, then precondition, then return contents, then the sibling cross-reference. The only redundancy is that the return-contents sentence and the `get_event` comparison sentence both describe the same list, making the close slightly repetitive.

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 takes on the job of describing return values, and it does so concretely. For a one-parameter read tool with full annotations this is essentially complete; only the failure mode for non-reserve events is left unstated.

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 already documents itself as "Event slug from list_events", so the description largely restates the schema ("Pass the event slug from list_events"). No extra format or provenance detail beyond that, 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?

Names a specific verb and resource ("Get ticket types and prices for an event") and scopes it to events whose `purchase.mode` is "reserve". It also explicitly distinguishes itself from `get_event`, so an agent can separate the two without opening schemas.

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 a real precondition (the event must be sold through this site with `purchase.mode` = "reserve") and tells the agent where the argument comes from (`list_events`). It also names `get_event` as an overlapping alternative, though it stops short of saying "prefer that one when you also need event details".

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