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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the description only needs to add operational context — and it does: sort order, the two fields returned, and the pagination convention ('Pass next_cursor back as cursor for the next page'). It omits what happens when the cursor is exhausted or page is empty, which is a minor gap.

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?

Three sentences, each doing distinct work: what is returned, why to call it, how to paginate. No filler and the crucial scope/ordering detail is front-loaded.

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 zero-required-param read-only list tool with fully described schema and explicit annotations, the description covers the only things left open: return fields, ordering, and pagination. Nothing an agent needs in order to call it correctly is missing.

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?

With 100% schema coverage the baseline is 3, but the description adds genuine meaning by explaining the output-to-input round trip between next_cursor and cursor. limit and uid are left to the schema, which already documents both adequately.

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 and resource ('List the user's chats') plus scope ('as they appear in the app.ugcagent.app sidebar'), ordering ('newest first') and returned fields ('id and title'). This separates it cleanly from get_chat and the many other list_* siblings.

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?

Explicitly routes the agent downstream: 'Use it to find the chat_id to pass to rename_chat.' It does not name the alternative for reading message content (get_chat) or state exclusions, so it falls short of a full when/when-not pair.

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