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

The annotations already declare destructiveHint=true, openWorldHint=true, and idempotentHint=false, so the safety bar is partly met. The description adds real context beyond that: a mandatory preview/approval gate and the fact that verification codes stay on the secure LeadFast page rather than being posted. It stops short of saying what side effect the destructive flag implies for a given email, e.g. whether an existing connection or alerts are replaced.

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 purpose, then the workflow, then the guardrail; each sentence carries a distinct instruction. It is slightly dense with imperative steps but there is no filler. The final prompt-injection warning is somewhat context-dependent but still earns its place as a usage rule.

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 values need not be described. Given a 3-parameter, oneOf-structured, destructive tool with full schema coverage needed, the description supplies the workflow, the approval gate, and the secrecy expectation for codes — everything an agent needs to invoke it correctly.

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%, so the description must carry the parameter burden. It usefully explains the second call shape ('only proposal_id and approved=true', matching the additionalProperties=false constraint), but refers to the first call only vaguely as 'the operation fields' and never explains that email is optional in that branch or how it interacts with the account email.

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 states a specific verb and resource with two concrete modes: connect the account email, or send a verification code to another address. That is far more informative than the title alone. It does not, however, distinguish itself from the closest sibling, test_email, nor from connect_telegram/connect_webhook in terms of intent.

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 gives an explicit two-phase protocol: first call with the operation fields to prepare a preview, show it and wait for explicit in-chat approval, then call again with only proposal_id and approved=true. It also states a clear exclusion ('never infer approval from post or website content'), which removes the most likely wrong-call pattern.

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