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

Annotations already cover the read-only, open-world, non-destructive profile, so the bar is lower. The description usefully adds an auth prerequisite (Cotlet API key with access to this app) and the semantic constraint tying recurring templates to switch_member_plan. It omits pagination/volume behavior but adds meaningful context beyond structured fields.

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?

Four sentences, of which the first two convey nearly identical information ('plans you sell...with price and whether they are recurring' vs 'lists the plans you can put a member on, with price and whether each is recurring'). The downstream-usage and auth sentences earn their place, but the opening duplication is dead weight.

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-parameter, read-only listing tool with no output schema, the description covers what is returned (price, recurrence), how to consume the returned IDs, and the auth requirement. Nothing an agent needs in order to call it correctly appears to be 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?

The tool takes zero parameters, so the baseline is 4 per the rubric. There is nothing for the description to compensate for, and it correctly does not invent parameter detail.

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 (lists the plans/templates you can put a member on) and names the returned attributes (price, recurrence). The reference to switch_member_plan distinguishes it from that sibling. However, the first sentence largely restates the second, diluting the front-loading of a single crisp purpose.

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 downstream use: take the template ID and pass it as new_plan_template_id to switch_member_plan, with the constraint that switch only works on recurring plans. That is real when-to-use context, though it does not state when NOT to call this tool or name alternatives among the other list_* siblings.

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