ga4_get_metadata

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description still adds value by clarifying the return shape is names only ('this tool does not return the numbers') and that custom definitions are included. It stops short of describing pagination or response volume, so a 4 rather than 5.

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 with no filler: the first defines the output, the second states the trigger, the third routes to the sibling and rules out a false expectation. The most important constraint is front-loaded.

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 single-parameter read-only metadata tool with no output schema, the description tells the agent what it gets (names plus custom definitions), what it does not get (numbers), and the workflow it feeds into. Nothing needed to invoke it correctly 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?

Only one parameter, and schema description coverage is 100%, so the schema fully documents property_id (with both ID formats). The description adds nothing about the parameter, 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?

States a specific verb and resource: 'List the dimensions and metrics a Google Analytics 4 property accepts.' It also delimits scope ('including custom definitions') and explicitly distinguishes itself from the reporting sibling by noting it does not return numbers.

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?

Gives an explicit trigger ('when a report needs valid metric and dimension names and guessing would be wrong') and names the follow-up tool and sequence ('Call ga4_run_report once the names are known'). The alternative tool is named and the ordering is unambiguous.

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