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

Annotations already declare readOnlyHint=true, and the description adds data-refresh behavior ('daily refresh, history to 1987') and output composition. However, it omits the Gold-tier requirement for history (which appears in the parameter description) and any other limitations or side effects, leaving moderate transparency beyond the annotation.

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 efficient, front-loading the return value and data sources. It slightly repeats 'daily' (once in the parenthetical and again in 'Updates: daily'), but overall it is well-structured and doesn't pad.

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?

The tool claims to score by US zip code, yet the input schema has no zip-code parameter and the description doesn't explain how the target zip is supplied. This is a critical ambiguity that could lead an agent to invoke the tool incorrectly. Output fields are mentioned, but the input mechanism is incomplete, making the tool hard to use reliably.

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 sole parameter 'days' has a thorough schema description (returns history series, max 5 years, Gold tier requirement), giving 100% schema coverage. The main description does not discuss parameters, which is acceptable since the schema fully explains it, but it also does not clarify how the required zip code is provided—an important gap.

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 clearly states the tool returns a 0-100 demographic-affinity score for retail site selection by US zip code, with specific data sources (Census ACS, proprietary weights) and output fields (score, trend, confidence, top_drivers). This distinguishes it from generic demographic tools in the large sibling list, and the title reinforces the site-selection purpose.

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 lists call scenarios: 'where to open a store, zip-code site screening, trade-area demographic fit, timing lease commitments, market entry, or new-store openings.' It provides clear context but does not mention when not to use the tool or name alternatives, which would push it to a 5.

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