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

The readOnlyHint annotation already covers the safety profile. The description adds useful behavioral context by clarifying that ranking is based on the count of distinct guides and that results can be filtered by theme. It does not disclose pagination, result shape, or aggregation details beyond that, but the annotations lower the burden here.

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?

Three short sentences, each earning its place: the core functionality, the intended use case, and the differentiation from a sibling. The most important information is front-loaded and there is zero filler.

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 ranking tool with fully documented parameters and no nested objects, the description is nearly complete. It explains the ranking semantics, optional filtering, and the intended use case. The only minor gap is that no output shape is described, but for a simple list-returning tool this is a low-cost omission given the clear semantics.

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% for all three parameters, so the schema fully documents city, limit, and theme. The description only reiterates that theme is optional and that ranking is by guide consensus, adding no syntax or format detail beyond the schema. Baseline 3 is appropriate because the schema does the heavy lifting.

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 ('Rank'), resource ('restaurants'), and ranking criterion ('how many distinct guides feature them'), plus an optional theme filter. It also explicitly distinguishes this tool from find_guides by noting the difference in return type, so an agent can tell them apart without inspecting schemas.

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 gives clear use cases ('where can't I go wrong', safest-bet picks) and names find_guides as the alternative, explaining that this returns ranked restaurants while find_guides returns guides. It lacks explicit 'when not to use' comparisons against other siblings like top_rated or search_restaurants, but the provided context is sufficient for typical routing.

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