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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so safety is covered. The description adds useful scope framing ('public facts', 'public deadlines') implying private data is excluded, but says nothing about behavior on an unknown or malformed id.

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?

One front-loaded sentence with the verb and keying mechanism first. The trailing field enumeration is somewhat redundant given a full output schema, but it stays compact and readable.

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?

Annotations cover the safety profile, the schema fully documents the only parameter, and an output schema exists so return values needn't be spelled out here. Only error/edge-case behavior for a missing or invalid id is left unaddressed.

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?

Single parameter with 100% schema description coverage; the schema already says 'Event id from search' and enforces a pattern. The description's 'by its id from search' merely restates that, adding no new 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 ('public facts of one event by its id') and enumerates the fields returned, so the agent knows exactly what it retrieves. It implicitly separates itself from the list_* siblings by being single-event and id-keyed, though it never explicitly contrasts with them.

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?

'by its id from search' establishes the prerequisite chain: the id must come from a prior search call, which routes the agent correctly. There are no explicit when-not conditions or named alternatives beyond the search hint.

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