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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description usefully adds an external prerequisite ('Needs the user's Cotlet API key with access to this app'), which is behavioral context the annotations do not provide.

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?

Front-loads the resource and its key returned fields, and each later sentence adds a distinct instruction. Slight waste in restating the same content twice (the lead line and the first sentence say essentially the same thing about order count and last order date).

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?

Compensates for the absence of an output schema by describing the returned attributes (orders placed, last order date), and covers pagination via the well-documented limit/cursor params plus the auth requirement. Nothing critical to a correct call is 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?

Schema coverage is 100%, so the baseline is 3. The description goes beyond the schema by explaining the purpose of last_order_before ('to find retailers who stopped ordering'), adding intent that the schema's terse 'older than this date' phrasing does not.

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 retailers on your customer list') and immediately discloses the two interesting return fields (order count and last order date). It is unambiguously distinct from the other Faire listing tools such as faire_list_orders and faire_list_conversations.

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 names a use case for a parameter ('Use last_order_before to find retailers who stopped ordering') and a downstream workflow ('Pass retailer_id values to send_campaign'), giving an agent clear task context. It does not state when NOT to use the tool, so it falls short of a 5.

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