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

Annotations already declare a non-read-only, non-destructive, idempotent mutation, and the description adds value on top: plan gating, the prior-lookup prerequisite, and that webhooks are signed. It does not address what happens on duplicate watches or watchlist size limits, but the annotations carry the safety profile.

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 sentences, zero filler, and the core effect and plan requirement are front-loaded ahead of prerequisites and parameter guidance. Nothing is repeated from the schema or annotations.

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 no output schema, the description still explains the delivery mechanism and the entry prerequisite, which is what an agent needs to call it correctly. Missing only edge-case behavior, such as what happens if the carrier lookup does not exist or the watch already exists.

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 67% and the schema documents dot and webhook_url, but alert_email has no description. The description compensates partially by stating that alert_email and webhook_url are alternatives that can be combined ("or both"), a constraint the schema itself does not encode via anyOf.

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?

States a specific verb and resource (watch a carrier) plus the observable effect: email and/or signed webhook on FMCSA record changes. This clearly separates it from list_watchlist and remove_from_watchlist, which manage rather than create watches.

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?

Gives real preconditions: paid plan required, Pro+ for webhook, and the carrier must have been looked up at least once. It also says to supply alert_email, webhook_url, or both. The only gap is that it does not explicitly contrast with batch_lookup or lookup_carrier as the prerequisite step.

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