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

Annotations declare readOnlyHint=false, openWorldHint=true, destructiveHint=false. The description adds that it sends an email and creates an object upon link opening — useful side-effect disclosure beyond the annotations. However it doesn't state permissions, whether the created entity is replaceable, rate limits, or idempotency. Some behavioral value, but not rich.

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 sentences, front-loaded with the target user scenario and the action. Efficient, though the first sentence is a long conditional clause that slightly delays the core action.

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?

With 3 required params, no output schema, and only openWorldHint from annotations, the description should convey more about side effects (account creation, verification flow) and what the caller gets back. It covers the trigger and outcome but leaves gaps around return behavior and error cases.

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 100%, so each parameter (email, timeZone, confirmationId) is already documented in the schema. The description adds only that the email link goes to the sign-in address and that confirmationId is 'what they said yes to', echoing the schema. No syntax or format beyond the 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 explains the tool sends a verification email and that opening it verifies the address and creates the thing the user agreed to. But the verb+resource is vague — 'emails a link' rather than a clear imperative name like 'send verification email'. It describes a workflow rather than stating a crisp purpose.

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 a narrow scenario ('someone who started without an account and said yes to a proposal'), which implicitly tells when to use it, but never explicitly compares to siblings like capital_company_confirm or capital_company_ask. No when-not or alternative guidance.

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