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

Annotations already declare readOnlyHint=false, destructiveHint=false and idempotentHint=false, so the agent knows this is a non-destructive, non-idempotent mutation. The description adds useful operational context the annotations cannot: where defaults come from, what to do when they are missing, and the expected next call in the workflow.

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?

Front-loaded with the action and scope, then defaults-sourcing, then param formats, then the next step — a sensible ordering. Slightly dense with an awkward line break mid-sentence, but nearly every clause carries 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?

An output schema exists, so return-value explanation is unnecessary, and the description covers the workflow gap around default values and the natural successor tool. The only hole is the optional industry_category, which is undocumented anywhere in the definition.

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 0% (titles only), so the description carries the burden — and it does for the two error-prone params, specifying time_zone as an IANA name with an example and currency_code as ISO 4217 with an example, plus the accounts/<id> format for account. display_name is self-evident, but industry_category is left entirely unexplained in both schema and description.

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 ('Create a GA4 property') and pins the parent scope ('under an Analytics account (accounts/<id>)'), including the resource-name format. An agent can distinguish it from ga4_update_property and the other ga4_create_* siblings without opening a schema.

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 real routing guidance: pull time zone and currency from get_org_context (the Analytics card's property_defaults), and if absent, ask the user rather than guessing. It also names the follow-up step, ga4_create_data_stream. It does not, however, contrast this with ga4_provision_account, which is the nearest alternative for account/property setup.

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