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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is fully covered elsewhere. The description adds only the enumeration of valid values, which largely restates the schema enums, and says nothing about return shape, pagination, or caching.

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?

A single front-loaded sentence with no filler. It loses a point only because the trailing enumeration duplicates the schema enums rather than adding new information.

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?

This is a simple read-only listing with two optional filters and no output schema; the description conveys the resource and the returned value categories adequately. It could note that an unfiltered call returns all basemap types/themes, but nothing essential for invocation is missing.

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% and both optional filters (type, theme) are fully described with enums in the schema. The description's mention of 'light, dark, vector, raster' and 'DEM' maps loosely onto those enums but adds no syntax or filtering semantics beyond what the schema already provides, so the baseline 3 applies.

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 names a specific verb ('List') and resource ('basemaps available to a project'), and the enumerated values make the scope concrete. It implicitly contrasts with the mutating sibling geobble_project_set_basemap, but never names it explicitly, so it stops short of a 5.

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 only implied: an agent can infer this is a discovery call to run before geobble_project_set_basemap, but the description never says when to use it or what the alternative is. No preconditions or exclusions are stated.

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