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

Beyond the annotations, the description discloses the exact return shape (`{ status, cartId, skuId, remainingLineCount }`), the structured error reasons (CART_NOT_FOUND / LINE_NOT_FOUND / BACKEND_BAD_REQUEST / BACKEND_UNAVAILABLE), and the authentication failure behavior with error code -32001 and data.code=MCP_API_KEY_REQUIRED. These are meaningful behavioral details not inferable from readOnlyHint, destructiveHint, or idempotentHint alone.

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 description is well-structured with a leading one-sentence purpose, a return contract, an alternative routing, error semantics, and an auth note. Every section adds actionable information and the structure is front-loaded so the most essential facts appear first. No filler or repetition.

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 tool with no output schema, the description covers the key operational needs: what action is performed, what the response looks like, how failures are surfaced, how this tool differs from its closest sibling, and what authentication is required. An agent has enough to invoke it correctly and handle outcomes.

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 description carries the burden of explaining both parameters. It clarifies that skuId identifies the line to delete, but never explains cartId's role or how to obtain/format either value beyond what the schema's names and minLengths already imply. This is a notable gap for an otherwise thorough description.

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 opens with a specific verb and resource: 'Remove a product line from a droplinked cart by skuId.' It immediately clarifies the granularity (line-level removal via skuId) and distinguishes itself from the sibling cart.updateLineQuantity for quantity changes. This leaves no ambiguity about what the tool does.

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?

The description explicitly states when not to use this tool: 'To change quantity (not remove entirely) use cart.updateLineQuantity instead.' It names the alternative sibling directly and gives the condition that selects it. Auth expectations are also clearly scoped, so an agent knows the operational context before calling.

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