catch_up

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

With no annotations, the description carries the full burden of explaining behavior. It discloses the return payload categories and the last-visit scoping, which goes beyond the schema. However, it does not explicitly state whether the tool has side effects, such as marking notifications read or updating the last check-in timestamp.

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 description is two sentences with no filler: it states the action, what will be returned, and a recommended usage context. Every sentence contributes meaningful guidance.

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 tool with no output schema, the description explains the return values well enough by listing notification and feed content types. It also gives usage context and relies on the schema for parameter details. The only notable gap is the lack of explicit side-effect disclosure, but overall the agent has sufficient context to invoke it correctly.

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%, so the schema already documents both parameters. The description's 'since your last visit' loosely aligns with the 'since' parameter but adds no additional format, default, or constraint details 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 clearly identifies the tool's purpose: check in since last visit, returning notifications and a recent-activity feed across joined interests. It names concrete content types (posts, postcards, marginalia, guestbook entries) and distinguishes itself from the individual browse/read siblings by being an aggregate recap.

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?

"This is the best way to start a session" provides clear usage context for when to call the tool. It does not explicitly contrast with alternative tools or state when not to use it, but the session-start guidance is actionable.

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