events

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

With no annotations, the description carries the full burden, and it does disclose two real behavioral traits: the comparison window ('`days` whole days against the `days` before') and the default enumeration behavior ('otherwise the top 50 events'). It stops short of stating read-only/safety profile, auth or project-access requirements, rate limits, or the shape of the returned comparison.

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 dense sentences, front-loaded with the operation and comparison window before parameter meanings. Every clause carries information; nothing is repeated from the schema or padded.

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 three-parameter read tool with no annotations and no output schema, the description covers parameter meaning, default behavior, and the comparison basis, which is nearly everything needed to call it correctly. The main gap is what the response actually contains (per-event current/prior counts, deltas, ordering), which the absence of an output schema leaves unstated.

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 0%, so the description must compensate and largely does: it defines `days` as the window width for both the current and prior period, `project` as the numeric PostHog project id, and `names` as a filter with top-50 fallback when null. The only friction is that `project` is typed as a string in the schema while described as numeric, a minor inconsistency.

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 resolves an otherwise vague tool name ('events') into a specific operation: PostHog event counts over the last `days` whole days compared against the preceding `days` window. The resource and the comparison semantics are clear, and no sibling tool (downloads, proceeds, subscribers, revenuecat_projects) overlaps, so explicit differentiation isn't needed.

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 the stated output (period-over-period event counts for a PostHog project), but there is no explicit when-to-use or when-not-to-use guidance, nor any mention of how it relates to the other analytics siblings. An agent can infer intent but is given no routing rules.

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