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

Beyond the annotations (which already mark it non-read-only, non-destructive, idempotent), the description discloses the blast radius: email addresses and page addresses are explicitly left unchanged, only display/sender names change. It also adds authorization requirements, the owner_required error for insufficient keys, and cost (free), which annotations cannot express.

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?

The core meaning is front-loaded, but the first sentence is a long run-on that chains display surfaces and the account_set_brand contrast together, and the duplicated trailing "Free. Free." is wasted text that reads as an artifact.

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 single-parameter mutation with no output schema, the description covers what changes, what is preserved, who may call it, and cost — enough for correct invocation. The only gap is return/confirmation behavior after the rename succeeds.

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 0%, so the description must carry parameter meaning; it does explain semantically what the single `name` argument controls across four surfaces. However, it adds nothing about the accepted format or the 2–120 character constraint, so an agent still must inspect the schema for validity rules.

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 concrete verb and resource ("Change the business's name") and immediately enumerates the exact surfaces affected: account name in emails, owner's page, account list, and sender name on customer-facing emails/pages. It explicitly contrasts with the sibling account_set_brand, so an agent can route between the two without opening either schema.

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 explicit caller eligibility (the owner's or an admin's assistant, the company-wide team's key) and the failure mode for other keys (owner_required), which is real when-to-use guidance. The alternative account_set_brand is named, though the phrase "while account_set_brand sets none" is ambiguous about what exactly brand leaves unset.

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