ga4_metadata

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

With no annotations provided, the description carries the full burden and does reasonably well: it discloses the required API enablement, the 'Lector (Viewer)' role required in the GA4 property, and that access failures return an error explaining how to fix them. It doesn't describe output shape or whether custom fields are always included versus gated by custom_only, but the prerequisite and failure behavior are unusually well covered for an unannotated tool.

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 purpose and the 'use before' rule are front-loaded, and every sentence carries information. Minor deductions for verbosity in the access paragraph and a language mix ('Lector (Viewer) en la propiedad de GA4') inside an otherwise English description.

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, non-destructive listing tool with a fully described 4-parameter schema, the definition covers purpose, prerequisites, ordering relative to ga4_run_report, and failure handling. What remains unstated, mainly output structure and pagination/size expectations for the longer with_descriptions output, is modest for this 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?

Schema description coverage is 100%, so all four parameters are already documented in the schema; the description only reinforces that customEvent:* entries appear in the result, which corresponds loosely to custom_only. It adds no syntax, default behavior, or combination guidance beyond the schema baseline.

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 opens with a specific verb and resource: 'List the dimensions and metrics available in the GA4 property', and adds a concrete scope detail about customEvent:* parameters. It does not explicitly distinguish itself from siblings like ga4_custom_dimensions or ga4_custom_metrics, which an agent might reasonably confuse it with, so it falls 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?

It gives an explicit sequencing rule ('Use before ga4_run_report to find valid API names') and names an alternative, ga4_check_access, for diagnosing access problems. It stops short of stating when-not-to-use or how it differs from the dedicated custom-dimension/metric siblings, so it is clear but incomplete.

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