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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds behavior beyond that: ordering (most recent first), a hard cap of 100 results, the fields returned, the status vocabulary, and the authentication requirement (POLYRANK_API_KEY on a paid plan). The auth/plan note is especially useful context an agent can't infer from annotations.

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?

It is one dense sentence plus a routing clause and an auth note – no filler, and the resource and ordering are front-loaded. The parenthetical plan remark is slightly repetitive ("a paid plan" stated twice), which costs it a point.

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?

With no parameters, no output schema, and rich annotations, the description covers what an agent needs: returned fields, ordering, result cap, follow-up tool, and auth requirement. Only minor gaps remain, such as whether the 100 cap is a truncation limit requiring any further paging behavior.

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 tool takes zero parameters, so the baseline is 4 and there is nothing for the description to clarify. It correctly avoids restating parameter rules and instead spends its words on return shape and auth.

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?

"Your Lab assistant chats, most recent first (at most 100)" gives a specific verb+resource, the ordering, and the result cap, then enumerates the returned fields (id, title, status) with the possible status values. It also points to polyrank_lab_get_chat for the single-chat case, so an agent can distinguish it from the sibling without opening the schema.

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?

The description explicitly routes the agent: list here, and "Read one with polyrank_lab_get_chat" for a single chat. That's clear context plus an alternative. It doesn't state exclusions (e.g., when to use polyrank_list_lab_templates or whether chats can be filtered), but for a zero-argument listing call nothing further is needed.

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