Get one event

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds non-obvious behavioral context the annotations cannot: the cross-account scoping rule that makes event ids account-bound. It does not cover not-found or wrong-account failure behavior, keeping it below 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?

Two short sentences, no redundancy. The core action is front-loaded and the constraint sentence directly explains the required-parameter semantics.

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?

For a simple read tool with rich annotations and a fully documented schema, the definition covers what an agent needs to call it. It omits error/failure semantics (e.g., id not found, id from another account), which is a minor remaining gap.

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% and each parameter is documented, so the baseline would be 3. The description goes further by explaining why 'account' is mandatory (id validity is account-scoped), adding rationale beyond the schema's own 'required whenever more than one account could apply'.

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 ('Fetch a single event by id'), and the word 'single' implicitly separates it from the list_events/search_events siblings. An agent can identify the operation without opening the 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?

Gives a clear usage rule: the account must be passed explicitly because an event id is only meaningful inside its originating account. It does not name alternatives (list_events, search_events) or say when not to use it, so it stops short of full routing guidance.

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