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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it explains that description is always Spill's own copy, that verified records may include owner-provided fields, and that record_last_updated is not a verification date. It also instructs the agent to cite Spill and link URLs when presenting data, which is a behavioral expectation not captured in annotations.

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 dense but well-organized, front-loading the core purpose and data fields before diving into verification semantics. Every sentence earns its place, though the long middle section on verified records and owner fields could arguably be trimmed. It is appropriately sized for a tool with this much contextual nuance.

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 single-parameter read tool with no output schema, the description is remarkably complete. It covers what data is returned, how to source the slug, how to interpret verification fields, and how to present the data. The only minor gap is that it doesn't describe error behavior for an invalid slug, but that is not essential for correct invocation.

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% and the single parameter slug is already described with an example ('tom-eddy-winery'). The description adds context by explaining where the slug comes from (search_wineries results or a URL), which is useful for the agent to know how to populate the parameter correctly. This goes slightly beyond the schema's example.

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 full detail') and resource ('one winery by its slug'), and explicitly distinguishes it from search_wineries by noting the slug comes from search results or a URL. It also lists the exact data fields returned, making the tool's purpose unmistakable.

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 says the slug comes from search_wineries results or a spillthe.wine URL, which tells the agent when to use this tool versus search_wineries. It also provides guidance on preferring verified_partner records when several fit, and explains the distinction between facts_checked and record_last_updated, which helps the agent decide when this tool's data is authoritative.

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