Update Product

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

Annotations already declare mutation, non-destructiveness, idempotency, and open-world access, so the safety profile is covered. The description adds genuinely useful behavior the annotations cannot: the duplicate id requirement as an API quirk, that sku and title must be resupplied even if unchanged, and specific error semantics (400 validation, 404 not found, 409 SKU conflict). It does not discuss side effects such as whether a SKU change affects existing orders, 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?

Front-loaded with purpose, then structured headers for required fields, optional fields, returns, errors, and usage. It is longer than needed because the required/optional field lists duplicate schema content, but every section is scannable and nothing is buried.

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 mutation tool with a nested object, an output schema, and full annotation coverage, the description supplies what structured data cannot: the API's duplicated-id requirement, error responses, and concrete use cases. An agent has everything needed to construct a correct call on the first attempt.

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 100%, so the schema already documents every field including the top-level/object id duplication and units (metres, kilograms). The description largely restates the required and optional field lists, and its one real addition — that sku and title 'can be the existing SKU unchanged' — implies full-object replacement rather than a partial patch. That is helpful but marginal, so baseline 3 is right rather than higher.

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 ('Update an existing product in the StarShipIt product catalogue') and adds the keying mechanism ('by its numeric ID'). This clearly separates it from starshipit_add_product, starshipit_list_products, and starshipit_delete_products without the agent needing to open 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?

The 'Use this tool when' block gives three concrete scenarios (fixing dimensions, adding HS codes, updating price/customs description) that map to real intents, and 'obtain via starshipit_list_products' points to the prerequisite lookup. It stops short of naming exclusions or the create/delete alternatives explicitly, so it is clear context without full routing.

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