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

With no annotations, the description carries the full behavioral burden and says nothing beyond "update". It does not disclose whether this is a partial or full replacement update, what happens to the 12 optional fields when omitted, whether changes are reversible, or what validation/errors to expect — critical for a 13-parameter mutation.

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?

A single front-loaded sentence with zero waste and no hedging. It is efficient, though the terseness is partly under-specification rather than disciplined brevity.

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 13-parameter mutation with no annotations and no output schema, the description is far too thin. The agent cannot tell whether omitted fields are preserved or nulled, whether stock fields are validated against the stock module, or what a successful response returns.

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 every parameter including enum-like semantics (product_kind, stock_tracked, min_stock_level) is already documented in the schema. The description adds nothing parameter-specific, so the baseline 3 is appropriate.

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 by ID") and names the addressing key, so intent is unambiguous. It does not differentiate against siblings such as create_product, delete_product, or search_products, but the verb alone carries that weight reasonably well.

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?

No statement of when to use this versus create_product or delete_product, and no prerequisites such as required permissions or required prior state (e.g., the product must already exist). The only routing hint is buried in the schema ('from search_products'), not in the description.

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