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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered; the description still adds real value by disclosing the required OAuth scope (favorites:write) and that buyer/order state changes. It does not elaborate on reversibility or rate limits, but it goes beyond the annotations rather than repeating them.

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, zero filler, with the core action and the sibling disambiguation front-loaded ahead of the scope/auth details. Every sentence carries distinct information.

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 single-param mutation with an output schema, the description covers the identifier source, the boundary against basket removal, the auth scope, and the state-change side effect. 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 coverage is 100% and the schema description already explains the product_id provenance and warns against SKU/article or basket item IDs, so the description's restatement adds little new meaning. Baseline 3 applies when the schema does the heavy lifting.

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 ('Remove a saved product from this buyer's favorites') and immediately disambiguates the identifier ('product_id from get_favorites, not a basket item_id'). An agent can distinguish it from remove_cart_item and add_favorite without opening any 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?

Explicitly names the alternative ('use remove_cart_item for that') and the condition that selects it, and clarifies that this does not touch the basket. The routing decision is fully specified rather than inferred.

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