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

Annotations already declare readOnlyHint=true and destructiveHint=false, but the description adds significant behavioral context: never to begin_agent_link again, never to ask owner to edit connector settings, never to web-search, and how to handle sessionId retry. These go beyond the annotations and guide the agent's behavior in observed situations.

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 long and dense, but every sentence carries actionable information: purpose, exclusions, special cases, triggers, and authentication notes. It is front-loaded with the core purpose and then expands into usage nuances. While not brief, it avoids fluff and structures information logically, though readability could benefit from bullet points.

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 tool that returns a rich set of preference data and has many sibling tools, the description covers everything an agent needs: return contents, when to call vs alternatives, category-specific instructions, sessionId handling, and explicit don'ts. There is no output schema, but the description lists what is returned. It is complete enough to invoke correctly in all contexts described.

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% (both parameters have descriptions), but the tool description enriches semantics further: it lists all valid category keys, emphasizes that category=sport is mandatory for sport-related buying flows, and explains that sessionId must be reused from begin_agent_link/poll_agent_link and never invented. This value is not in the schema.

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 states a specific verb ('Get') with a precise resource ('user's category preferences') and enumerates the returned fields (fat %, brands, sizes, pets, sport macros, schema, learned signals, onboardingPurposes). It also lists the categories and explicitly differentiates from siblings like list_purchases and search_products by stating when each is appropriate.

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?

Extremely detailed usage guidance: it specifies exactly when to call (before search_products only when owner asked to buy/look in AgentPay), when not to call (idle advice), special handling for sport categories, triggers like 'мой бренд' and 'заполни предпочтения', and when to substitute list_purchases for phrases like 'как обычно'. It even covers retry logic with sessionId.

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