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

Annotations already declare readOnlyHint=true, covering the safety profile. The description adds value by specifying what the response includes (name and current state), which is useful context about the return value. No contradictions, and no additional behavioral traits (like error cases) are required for a simple getter.

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?

A single, focused sentence with no redundant words. The core purpose and the returned fields are front-loaded, and every phrase earns its place. Excellent structure.

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 one-parameter read tool with no output schema, the description is fully complete. It specifies what is returned (name and current state) and the selection criterion (by ID). An agent has everything needed to call 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% for the single parameter (list_id), so the schema already documents it. The description does not add further detail about the parameter, but the baseline of 3 is appropriate since the schema carries the semantic load. No additional explanation needed.

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 states a clear verb ('Get'), a specific resource ('one list by its ID'), and the scope ('including its name and current state'). It clearly distinguishes from sibling tools like list_lists (which lists many) and get_list_subscribers (which retrieves subscribers, not the list itself). No ambiguity.

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 implies when to use it: when you have a specific list ID and need that single list's details. It does not explicitly name alternatives or exclusions, but the purpose is unambiguous given the wording. In a large sibling set, mentioning 'instead of list_lists when you have an ID' would have been ideal, but it's not necessary for correct usage.

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