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

Annotations already indicate read-only, idempotent, non-destructive, and open-world hints. The description adds behavioral context: returns sorted results with connector types, power levels, and availability, and explains filtering purpose. This complements annotations well.

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 that are efficient and front-loaded with the core purpose. Every sentence provides value without redundancy.

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 presence of an output schema (as per context signals), the description adequately covers input parameters and output behavior (sorted by distance, including details). It is complete for a search tool with this level of complexity.

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 input schema has 100% coverage, and the description adds value by explaining the default radius, and for connection_type_id provides example mappings (25=Type2, etc.) and notes that min_power_kw is for DC fast charging. This goes beyond the schema descriptions.

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 it finds nearest EV charging stations to GPS coordinates within a radius. It specifies sorting by distance, connector types, power levels, and availability, and mentions filtering by power and connector type. This is specific and distinct from siblings like ev.charging.details and ev.charging.search.

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 explains the default radius and filtering options, and implies the tool is for proximity-based searches. It does not explicitly contrast with siblings or provide when-not guidance, but the context is clear enough for agents to decide when to use it.

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