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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds value beyond them with the sort order, the returned fields, and a cost disclosure ("Free"). It stops short of stating pagination behavior or whether the response includes a total count, leaving a modest 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 short blocks: purpose with ordering, then two concrete call sites, then a one-word cost note. Front-loaded, no repetition, and every line carries information an agent would otherwise have to guess.

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 two-parameter read with no output schema and full annotation coverage, this is close to sufficient: it says what comes back (lists with size and metrics) in what order, and when to call it. The missing piece is pagination and total-count behavior, which matters since limit defaults to 25 and users may have more lists.

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 both limit and include_archived are fully documented in structured fields, which sets the baseline at 3. The description adds nothing about either parameter and never mentions that archived lists are excluded by default, which is the one behavioral nuance worth surfacing.

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 creator lists on this account") and adds ordering ("newest first") plus returned content ("size and metrics"). No sibling could be confused with this enumeration tool, so differentiation is achieved by the resource itself.

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?

Gives explicit call sites: before create_list to avoid near-duplicates, and after add_creators_to_list to confirm the count landed. This is real when-to-use routing against two named siblings rather than implied intent.

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