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

With no annotations, the description carries the full burden. It discloses the return fields, pricing ($0.05 per call with x402 payment), and coverage limitations. It does not detail error handling, rate limits, or behavior when no building is found, but the provided info is substantial.

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 repetitive: the first four sentences are essentially duplicated in a later block. It could be condensed into a single coherent paragraph without losing information, indicating poor conciseness.

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?

Given the complexity (3 parameters, no output schema, no annotations), the description covers return fields, use cases, pricing, and coverage. However, it lacks details on output format, error states, and edge cases, leaving some gaps for an agent.

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 coverage is 100%, so the schema already documents the three parameters (lat, lon, quality). The description only mentions 'Input: lat/lon (+imagery quality)' without adding meaning beyond the schema descriptions. 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 clearly states the tool returns rooftop solar potential metrics (max panel count, usable roof area, annual sunshine hours, carbon-offset factor) for a given coordinate, sourced from the official Google Maps Platform Solar API. This specific verb+resource combination distinguishes it from sibling tools like climate_risk_score or osm_building_footprint.

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 explicit use cases: 'sizing solar installs, real-estate energy scoring, or carbon/ROI estimates.' It also notes worldwide partial coverage with EU well covered, implying limitations. However, it does not offer exclusions or comparisons to alternative tools for similar tasks.

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