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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description contributes only the property-scoping detail; it says nothing about volume, pagination, or whether custom metrics and dimensions come back in separate sections, all of which matter for an open-world listing.

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 or redundancy. It is efficient, though its brevity leaves it short of the substance an agent needs.

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?

For a read-only listing tool with full schema coverage and safety annotations, the essentials are present. Still missing is any hint about output shape (are these two separate lists?) or the relationship to the create sibling, which is the main ambiguity an agent would face in this tool family.

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 property, folder, language and the summary/full detail enum are fully documented in the schema itself. The description only echoes the property scope; it adds no meaning about how 'detail' affects this particular listing.

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?

States a specific verb and resource ("List custom dimensions and metrics") and scopes it to "the selected property". It implicitly contrasts with the write-side sibling ga4_create_custom_definition, but never says so explicitly, so the differentiation is inferred rather than stated.

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?

There is no guidance on when to use this versus ga4_create_custom_definition, ga4_custom_report, or the other ga4_* listing tools. A reader learns only that it is a listing, and must guess that it should be used to audit existing definitions or to discover valid dimension/metric names before building a report.

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