Diff Since Last Check

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the 'Read-only' sentence mostly repeats structured data. The description does add useful context about the data source ('your activity stream') and the categories returned, but it does not disclose ordering, limits, or whether items are filtered by unread status.

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?

The definition is a single front-loaded sentence with no wasted text. It states the core action and scope first, then lists the change categories.

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 one-parameter read-only tool with complete schema coverage and rich annotations, the description provides enough information to select and invoke it correctly. It is slightly incomplete on return shape and result ordering, but those gaps are minor given the tool's low complexity.

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?

The single 'since' parameter is fully described in the schema with ISO 8601 format and an example, so schema coverage is 100%. The description clarifies that it acts as a time threshold for changed items, but adds no additional syntax or edge-case semantics beyond the schema.

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 gives a specific verb and resource: 'List what changed since a given time,' and enumerates concrete change categories (grades, announcements, discussion replies, inbox messages) from the activity stream. It clearly separates a diff-style feed from a generic stream listing, though it does not explicitly name the closest sibling alternative such as get_activity_stream.

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 'since a given time' and the enumerated change types, so an agent can infer this is for incremental change checks. However, there is no explicit when-to-use or when-not-to-use guidance and no named alternative such as get_all_unread or get_activity_stream.

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