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

With readOnlyHint=true already covering the safety profile, the description adds a genuinely important disclosure: 'Metadata only; revealed values are never stored or returned.' This bounds what an agent can expect from a PII-adjacent audit endpoint. Pagination/ordering behavior is not described, but the schema covers paging.

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 sentences, zero waste, and the ledger scope is front-loaded ahead of the usage guidance. Every clause earns its place, including the metadata-only guarantee.

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 read-only, zero-required-param list endpoint with a fully documented schema and no output schema, the description supplies what the schema cannot: the meaning of the ledger and the privacy guarantee. Return shape and ordering are left implicit, which is a minor gap for an audit-listing tool.

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%, including the non-obvious timezone semantics for startDate/endDate, so the schema carries the parameter burden. The description adds no filter syntax or date-format detail beyond what is already structured, making the baseline 3 appropriate.

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 (List) and resource (PII reveal audit ledger) with a precise enumeration of what it captures — who revealed which fact of which trace, and when. No sibling tool covers this audit surface, so it is distinguishable 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 clear usage context ('monthly access-log inspection and SIEM collection'), which tells an agent the scenario that selects this tool. It does not name an alternative tool or state when not to use it, so it stops short of explicit routing.

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