ga_send_login

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

The annotation readOnlyHint=false already indicates this is a mutation, and the description does not add significant behavioral context beyond that. It doesn't mention return values, side effects, or requirements. With no output schema, the description carries full burden but only restates the purpose.

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?

Two concise sentences. The first sentence states the action, and the second adds useful context about the event type. No wasted words.

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 send-event tool with no output schema, the description is adequately clear about the purpose but lacks details on expected behavior, return values, or prerequisites. Sibling tools like ga_send_event could be confused without explicit differentiation. Given the schema covers most parameters, this is acceptable but not rich.

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 schema covers 75% of parameters with descriptions, and the description adds minimal meaning by referencing 'authentication method,' which aligns with the 'method' parameter. It doesn't clarify relationships between parameters or the optional client_id, so it provides only marginal value beyond schema.

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 clearly states the tool's function ('Send a login event to Google Analytics') and specifies the event type, distinguishing it from siblings like ga_send_signup or ga_send_purchase. It uses a specific verb and resource.

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 provides clear context by stating it is the 'standard event for tracking user logins,' which tells when to use it. However, it does not explicitly mention alternatives or when not to use it, so it lacks explicit exclusion guidance.

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