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

Goes well beyond the annotations by explaining that the result is a terms_url the user must open once, that the account only exists after they accept, and that a refusal yields fallback=true with Google's own sign-up page. This is exactly the consent and failure behavior an agent cannot infer from structured fields.

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-loads the purpose, then layers in return behavior, sequencing, parameter guidance, and fallback handling without filler. It is dense but every sentence contributes; only the fallback sentence is slightly run-on.

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 provisioning tool with a consent link, the description covers purpose, required user action, sequencing, parameter format, and failure fallback. Even though an output schema exists, the description supplies the behavioral meaning an agent needs before calling.

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 0%, so the description must carry parameter meaning. It usefully explains region_code as a CLDR business country with examples, but says nothing about display_name, leaving half the parameters to inference.

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 (start a new Google Analytics account) and scopes it to a login that has none. This cleanly separates it from ga4_list_account_summaries and ga4_create_property, which it explicitly names as follow-on tools.

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 clear context for when to use it ('for a login that has none') and describes the subsequent workflow with ga4_list_account_summaries and ga4_create_property. It stops short of an explicit 'do not call if the user already has an account' warning, but the constraint is strongly implied.

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