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

With no annotations, the description carries the full transparency burden. It explicitly discloses that it is a deterministic database lookup, not LLM-based, and sub-second. It also gives coverage statistics. This provides solid behavioral expectations, though it does not cover edge cases like missing data or error behavior.

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?

Two sentences, highly informative, with the main purpose front-loaded and coverage/performance details following. Every sentence contributes value, making it concise and well-structured.

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 description covers purpose, geographic scope, data coverage, and performance, which is sufficient for a moderate-complexity lookup tool. With an output schema present, the lack of return-format details in the description is acceptable. It does not mention prerequisites or error handling, but these are not critical for this simple tool.

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 the baseline is 3. The description does not add additional parameter-level meaning beyond the schema; it only lists output types, not how parameters affect results. This is adequate but not enhanced.

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's function: 'Enrich a location with European building intelligence' and lists specific data types (roof surfaces, parking areas, solar-obligation status, existing installations). This is a specific verb+resource with concrete outputs, differentiating it from generic location or intelligence tools among siblings.

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 clear context on when to use: for European building data across 6 countries, with sub-second deterministic lookups. However, it does not explicitly name alternatives or state when not to use it, so it misses the full 5-level guidance.

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