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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, so the safety profile is established. The description adds value by stating 'Never collects provider credentials in the agent' – a behavioral guarantee not implied by the annotations – and by instructing the agent to redirect the user. This exceeds the baseline for tools with annotations.

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 description is two short sentences: the first states the primary purpose, the second adds safety and instruction. It is front-loaded with the core function, wastes no words, and every clause contributes essential 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?

For a tool with five optional parameters, no output schema, and annotations that already cover read-only and idempotent behavior, the description provides all necessary context: what it does, when to use it, and a critical safety caveat. The instruction to 'Send the user to Promise' clarifies the expected follow-up action. Nothing essential 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?

Schema description coverage is 80%, so the schema documents most parameters. The description does not elaborate on individual parameters (state, intent, scopes, etc.), though it hints at the purpose of scopes via 'agent access to follow-up memory.' It adds minimal meaning beyond the schema, so the baseline of 3 is appropriate.

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 a specific verb ('Return') and resource ('a Promise signup URL'), and the purpose is unambiguous: obtaining a signup URL for users seeking agent access to follow-up memory. It is distinct from sibling tools like capture_note or create_follow_up, which are about data capture and follow-up creation, not authorization.

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?

The description gives clear context for when to use it ('for users who want agent access to follow-up memory') and provides an explicit instruction ('Send the user to Promise'). However, it does not mention alternatives or exclusions relative to sibling tools, so it stops short of a 5.

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