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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so safety is covered. The description adds the useful ordering behavior ('newest first') but leaves 'recent' undefined — no time window, no mention of the default 25-row cap or whether results truncate silently.

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 clauses, front-loaded with the returned resource before the ordering detail. Efficient, though the extreme brevity is part of why the time-window ambiguity goes unaddressed.

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?

A simple two-parameter read with no output schema, so the bar is modest, and annotations carry the safety profile. Still, an agent cannot tell how far back 'recent' goes or what 'limit' maps to, which are the two things needed to interpret a call's result.

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 coverage is only 50%: the 'limit' parameter has no description anywhere, and the description adds nothing about it (default, max, truncation behavior). It also doesn't clarify what time horizon 'recent' covers, which is the key ambiguity for interpreting results.

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 resource (recent events/what the user did) and its ordering (newest first), which is more than the title 'User activity' conveys. It doesn't name query_events as the differing sibling, so the agent must infer the distinction, keeping it below a 5.

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?

No when-to-use guidance and no exclusions. With siblings like query_events, get_user, and find_users_without_event in the same namespace, the description never says when this per-user recent-events view is the right choice versus a filtered event query.

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