search_places

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered. The description adds real behavioral context beyond that: results are ranked by size when names collide, and lat/lon converts the ordering to distance-from-point.

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?

Three tight sentences, front-loaded with what the tool finds, then ranking behavior, then the optional distance-sorting hint. No filler.

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?

An output schema exists, so return structure need not be described. Purpose, ranking and sorting are adequately covered; the remaining gap is the undocumented `limit` cap and the pairing requirement for lat/lon, which an agent may need to call 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 coverage is 0%, so the description carries the burden. It explains the query format (full or partial postcodes, e.g. "S1") and the effect of lat/lon, but says nothing about the `limit` parameter or whether lat/lon must be supplied together, leaving half the parameters undocumented.

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 states a specific verb ("Find") and enumerates the resource types searched (towns, villages, postcodes, stops) plus the search axis ("by name"). This implicitly separates it from proximity-based siblings like nearby_stops and nearby_stations, though no sibling is named explicitly.

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?

Usage is implied: it is the name-search tool, and the note about supplying lat/lon hints at how to prefer distance ordering. There is no explicit when-to-use versus when-not, and no alternative tool is referenced for name vs proximity lookups.

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