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

readOnlyHint already tells the agent this is a safe read. The description adds useful non-schema context: pagination size (50 per page) and the scope of logged activities. It stops short of auth, rate-limit, or default-ordering behavior, which the schema's sort default partly covers.

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?

One front-loaded sentence that leads with the resource and page size, then filters, then the API mapping. The long event-type enumeration slightly overlaps the activity enum, keeping it just shy of a 5.

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, 100%-documented-schema list tool with no output schema, the description supplies page size and content scope. Return-value structure would be nice but the schema coverage and readOnly hint leave no critical gap for correct invocation.

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 100% with enums fully described, so the schema carries parameter meaning. The description only summarizes the filter axes (user, activity, time) without adding syntax beyond the schema's Unix-timestamp and enum details.

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+resource ('The school's activity log') and enumerates the concrete event types it returns, which no sibling (users, courses, payments, certificates) covers. An agent can immediately tell this is the event-stream tool.

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?

Implies usage via 'filterable by user, activity and time,' giving the agent a sense of when the tool applies, but names no alternative or when-not condition relative to siblings like list_payments or list_users.

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