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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds behavioral depth: it works identically to 'recommend', includes ingredient-aware scoring, safety notes, routine building, and returns scored products with checkout URLs. The deprecation warning is also valuable context, though further detail on response structure or edge cases is missing.

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 front-loaded with the critical deprecation notice, then succinctly covers purpose, usage guidance, and return value. Every sentence contributes to the agent's decision-making, with no wasted words.

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 read-only recommendation tool with fully documented parameters and a clear sibling alternative, the description covers purpose, when to use, what to expect, and the deprecation path. No output schema is needed since the return type is summarized. All necessary context for correct invocation is present.

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?

The input schema provides 100% coverage with detailed descriptions for brand, query, and strategy, so the description adds no additional parameter-level meaning. The mention of 'strategy override' is redundant with the schema. 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?

The description clearly states a specific function: obtaining a personalized skincare recommendation with ingredient-aware scoring, safety notes, and routine building. It explicitly distinguishes from search_products and even names the successor tool 'recommend', ensuring the agent understands the tool's unique role despite its deprecation.

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 states when to use ('when the user wants advice, has a skin concern, or asks what to buy') and when not to ('Do not use for browsing or listing products — use search_products instead'). It also provides an alternative tool due to deprecation, fully meeting the when/when-not/alternatives criterion.

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