List custom values

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

The annotations already declare readOnlyHint=true, so the read-only nature is known. The description adds useful context that the values are location-scoped and serve as reusable merge fields, but it does not disclose return shape, ordering, or pagination behavior.

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 a single, front-loaded sentence that states the operation and immediately clarifies the domain term with a parenthetical. There is no filler or redundant repetition of the title.

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 simple list operation with one optional parameter, full schema coverage, and readOnlyHint/openWorldHint annotations, the description is nearly sufficient. The main missing piece is an explicit statement of the return format since there is no output schema, but this is a minor gap for a straightforward list tool.

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 fully documents the only parameter, locationId, including its default behavior, so the description does not need to restate it. With 100% schema description coverage, the baseline score of 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 uses the specific verb 'List' with the resource 'location custom values' and clarifies what they are ('reusable merge fields used in templates/messages'), making the tool's purpose immediately clear. It also distinguishes this from related siblings like ghl_get_custom_value and ghl_list_custom_fields through the 'merge fields' framing.

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?

No explicit guidance is given about when to choose this tool over alternatives such as ghl_get_custom_value, ghl_create_custom_value, or ghl_list_custom_fields. Usage is only implied by the verb 'List' and the resource name, with no when-to-use or when-not-to-use conditions provided.

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