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

Annotations already cover idempotency and non-destructiveness, so the repeated-call sentence adds little, but the description contributes real behavior beyond them: a connected account, the catalog:write OAuth scope, and account tier limits. The tier-limit statement is not elaborated, which keeps it from a 5.

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 short sentences, front-loaded with the operation and scoping constraint, with no filler. 'Account tier limits apply' is the one vague clause that could have been made actionable.

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 mutation with an output schema and full annotation coverage, the description supplies the missing essentials: auth scope, account requirement, ownership constraint, and idempotent behavior. Only the specifics of the tier limits and the parameter level are thin.

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 0%, so the two parameters are bare strings with only length bounds. The description compensates partially by implying both IDs must reference owned resources, but adds no format, sourcing, or failure semantics for listingId/listId.

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 specific verb and resource ('Add one owned listing to one owned list') and constrains scope with the ownership qualifier, which separates it from sibling mutators like link_listing_to_cultivar and update_list. An agent can identify the operation 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?

Preconditions are implied (the listing and list must already be owned/created), but there is no explicit when-to-use guidance and no routing away from adjacent tools such as link_listing_to_cultivar or update_listing. The agent must infer the appropriate moment to call this.

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