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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so the safety profile is covered. The description adds the auth requirement (Cotlet API key with access) and the field set, but nothing about latency, pagination, or failure modes.

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?

The field list is stated twice ('Full listing: title, description, price, additional license price, grades, subjects, tags, formats and files' then 'Returns one listing in full: description, price, additional license price...'), which is redundant. The usage guidance is front-loaded reasonably, but the duplication costs it.

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?

With a single fully-documented parameter, no output schema, and annotations covering safety, the description is complete enough; enumerating returned fields compensates for the absent output schema. Minor redundancy aside, an agent has what it needs 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 coverage is 100% and product_id is fully documented ('Product ID from list_products'), so the schema carries the load. The description adds no syntax or format detail beyond that baseline.

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+resource (get a single Teachers Pay Teachers product listing) and enumerates the returned fields, distinguishing it conceptually from list_products and get_product_stats. It does not explicitly name a sibling, so it falls short of a 5.

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 concrete trigger conditions: 'Use it before answering a buyer question or rewriting a title, so your agent works from the real listing.' Clear context for when to reach for it, though it does not name alternatives or exclusions.

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