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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, so the description does not need to restate safety. It adds useful context that the result is 'compared to the forecasted level for this hour,' which is a meaningful behavioral nuance. It does not mention errors or rate limits, but the annotations lower the burden.

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 concise sentences: the first states the core question and output, the second explains the two identification methods and includes an example. No filler words, and the most important information is front-loaded. It is well-structured and efficient.

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, semantically simple tool with four parameters and no output schema, the description provides everything an agent needs: the purpose, the identification methods, and a full example. There is no ambiguity about how to invoke it or what the query represents. The absence of output format details is acceptable in this context.

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%, so each parameter is already documented. The description adds value by grouping venue_name + venue_address as an alternative to venue_id and giving a concrete example of all parameters. This clarifies the conditional relationship that the schema encodes only implicitly.

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 and resource: 'returns live foot-traffic busyness compared to the forecasted level for this hour.' It clearly differentiates the tool from sibling besttime_forecast by emphasizing 'right now' and 'vs usual.' An agent can understand the tool's purpose without opening the schema.

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 first sentence — 'Is <venue> busy right now vs usual' — provides a clear context for when to use this tool: real-time busyness comparison. It does not explicitly name alternatives like besttime_forecast, but the 'live' vs 'forecasted' framing makes the use case distinct. This qualifies as clear context without explicit exclusions.

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