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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so "Read-only" is largely redundant. The description does add genuine context beyond them: the account-token auth requirement and the word "recent," which hints at a bounded result window. It says nothing about rate limits, pagination, or how many messages are returned.

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 short fragments with no filler, and the prerequisite plus operation are front-loaded before the read-only note. It is appropriately tight, though the parenthetical auth note leads rather than the tool's purpose, which slightly weakens the opening.

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 one-parameter, read-only tool whose annotations cover the safety profile, the definition is close to sufficient. However, with no output schema, "recent" is left undefined (count, time window, ordering), leaving the agent unsure what the call will actually return.

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?

There is a single parameter with 100% schema description coverage, including a concrete example address, so the schema carries full parameter meaning. The description adds nothing about the site argument beyond what the schema already states; baseline 3 applies.

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 ("Lists") and a precise resource ("recent messages from a claimed site's contact form"), which separates it from the similarly named list_site_leads and list_site_files. It never explicitly names or contrasts a sibling, so it stops 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?

The description implies usage (read contact-form messages for a claimed site) and gives one prerequisite, the account token, but offers no explicit when-to-use, when-not-to-use, or alternative such as list_site_leads. Guidance 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.