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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: 'Coverage is uneven BY DESIGN — it follows where the author has actually eaten.' This discloses the tool's limitation (non-exhaustive, biased list) and explains why, which is critical for the agent to interpret results correctly. It does not mention response format, but given annotations, this is sufficient extra context.

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 two sentences of 41 words total. The primary purpose is front-loaded in the first sentence, and the second sentence delivers the critical caveat and usage call-to-action. There is no redundancy, filler, or unnecessary detail. Every word earns its place, making it an exemplar of efficiency.

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 with zero parameters, no output schema, and read-only annotations, the description covers everything an agent needs: what the tool does, the important caveat about uneven coverage, and explicit actionable guidance on when to call it. The return value is hinted at ('with how many venues each holds') which is sufficient given the lack of an output schema. No missing information would cause incorrect invocation or misinterpretation.

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 has zero properties, so there are no parameters to explain. The rule states a baseline of 4 for 0-param tools. The description does not contradict or attempt to describe parameters, and its mention of 'with how many venues each holds' pertains to output, not input. Thus the baseline score 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 opens with a precise verb and resource: 'List every city the Max Eats Out guide covers, with how many venues each holds.' It clearly defines the scope (all cities in the guide) and the output (counts per city). It also implicitly differentiates from siblings by framing this as the coverage-checking tool ('call this before assuming a city is covered'), which distinguishes it from get_city (single city lookup) and search_venues (venue search).

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 explicit when-to-use guidance: 'call this before assuming a city is covered rather than searching a city that is not in the guide.' This not only says when to use it, but also warns against a common mistake (searching a non-existent city and reporting no results). It clearly implies that search_venues should be used only after confirming coverage here, so the agent knows the relationship to alternatives.

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