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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true; the description's 'Read-only: nothing is saved or sent' reinforces and slightly clarifies that no data is persisted. It adds little beyond that — no mention of rate limits, per-call cost, or what happens to invalid addresses.

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?

Three tight sentences, front-loaded with the core purpose and the read-only guarantee before the endpoint detail. The 'POST /molpro/addressCorrection' line is marginal internal detail but not harmful.

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?

No output schema exists, so the description should explain what comes back — corrected/standardized address fields, per-address success or failure indicators. It doesn't, leaving the agent guessing about the response shape of a validation tool whose whole value is the corrected result.

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 compensate: it does say the input is up to 100 US postal addresses and implies which fields matter (validation requires address1/city/zip, state optional), but it never documents the item structure or the significance of name/address2. Partial compensation only.

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?

Specific verb+resource: 'validate and standardize US postal addresses' with the USPS/CASS standard named and a clear scope cap of 100. It implicitly separates itself from click2mail_create_address_list by stressing 'nothing is saved,' but never names a sibling explicitly, which keeps it short of a 5.

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?

'before mailing' implies the workflow position (pre-flight cleanup before creating a job or address list) but gives no explicit when-to-use/when-not or pointer to create_address_list for persistence. Usage is inferable rather than stated.

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