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

With no annotations present, the description carries the full disclosure burden and does a fair job: it declares the authorization requirement ('Owner only') and a data-safety guarantee ('Never contains secrets'), which an agent cannot infer from the schema. It does not state read-only semantics explicitly or describe pagination/ordering behavior of the returned history.

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 compact sentences with the access constraint front-loaded and no filler. Every clause (ownership, fields returned, no-secrets guarantee) earns its place.

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, single optional-parameter read tool with no output schema, the description covers authorization, the shape of the returned records, and a data-safety caveat. Only pagination/ordering nuance is absent, which is a minor 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% ('1-200, default 50'), so the single limit parameter is already fully documented in the schema. The description adds no further syntax or defaulting detail, making the baseline 3 appropriate when the schema does the heavy lifting.

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?

The description states a concrete verb-resource relationship ('the last uses of your vault') and enumerates the fields returned (who/bot label, login, domain, what happened), so an agent knows this is the activity/history listing. It is distinguishable from session-oriented siblings like open_session or session_fetch, but it does not explicitly contrast itself with the closest sibling, weekly_report.

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?

'Owner only' communicates a permission precondition, which is useful, but there is no guidance on when to call this versus weekly_report or other reporting tools, and no exclusions or prerequisites beyond the ownership note. Usage is implied rather than stated.

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