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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: coverage of 581 cities, measurement periods (1990–2000, 2000–2015), the LCR/PGR ratio interpretation (>1 indicates sprawl), and inclusion of built-up area per capita at three time points. This goes beyond the structured 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?

Four sentences, each earning its place: purpose, coverage, interpretation, and filters/use case. The core verb and resource are front-loaded, and there is no filler or redundant restatement of schema details.

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 is a simple read-only query with optional filters, an output schema exists, and the schema documents all parameters. The description covers coverage, time periods, metric interpretation, filters, and intended use cases, leaving nothing an agent needs to call it correctly.

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 all four parameters (city, limit, region, country) already have meaningful descriptions. The description only repeats 'Filter by country, city, or UN region' without adding syntax, formats, or behaviors not found in the schema. Baseline 3 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 'Retrieve city-level land consumption rate (LCR) versus population growth rate (PGR) data for SDG 11.3.1' – a specific verb and resource. It clearly distinguishes from sibling UN-Habitat tools (city_budget, open_spaces, transport_access) by naming the exact metric and SDG indicator.

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 provides a clear use context: 'Useful for sustainable urbanization and land-use planning analysis.' It does not explicitly name alternatives or state when not to use the tool, but the context is sufficient for an agent to select it over the other urban data tools.

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