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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuinely useful context beyond that: the response is JSON:API { data } and payloads may contain PII, plus the underlying REST route for cross-referencing. It stops short of noting auth requirements or not-found behavior.

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 tight sentences with the core purpose front-loaded and no redundant restatement of the title. The trailing REST path clause is marginal but serves as a useful cross-reference, not padding.

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 single-record read with no output schema, the description does the needed work: it sketches the return shape ({ data }) and flags PII sensitivity. Missing only minor operational details such as error/not-found behavior.

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?

Only one parameter and the schema already documents it at 100% coverage, including the 'evt_...' example, so the baseline is 3. The description restates the id concept without adding format, validation, or lookup constraints beyond the schema.

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 ('Get a single audit-trail event by id') and pins the scope to one record, which implicitly but clearly separates it from the sibling persona_list_events. An agent can tell what it retrieves 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?

Usage is implied by 'single ... by id' and the required event_id, so an agent can infer it is the lookup path vs. persona_list_events for browsing. However, no explicit when-to-use/when-not guidance or named alternative is given.

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