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

Annotations cover the safety profile (readOnly, idempotent, non-destructive). The description goes further with genuine behavioral context: visibility gating via public-directory opt-in, timezone-relative isOpenNow with null semantics for unknown hours, and sentinel conventions (null = not declared, never 'no'). Those conventions matter and aren't in the schema or 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?

Front-loaded with the verb and resource, which is good, but sentence one is a sprawling comma-separated field dump that runs dozens of items long, and the eligibility caveat is buried at the end. The information is useful but the density makes it hard to scan.

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-param read with no output schema, the description covers what gets returned, the null conventions, and the visibility gate. What's missing is pagination/size or any note on failure modes when a slug isn't public, but the important shape is conveyed.

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 slug parameter is fully documented in the schema including an example. The description adds no format or syntax detail beyond what the schema already provides, so the baseline 3 applies.

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?

Clear verb ('Fetch') and resource ('public restaurant profile by slug'), with a rich enumeration of the returned fields. It doesn't explicitly distinguish itself from sibling search_restaurants or get_restaurant_menu, but the field list makes the scope obvious to a reader.

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 closing sentence establishes eligibility ('Only restaurants opted into the public directory are visible'), implying when the tool will succeed. However, it never says when to use this versus search_restaurants or get_restaurant_menu, and gives no exclusion criteria.

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