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

Annotations flag destructiveHint and openWorldHint, but the description goes well beyond them: it discloses the 30-day forwarding window, that the old name becomes claimable by anyone afterward, that email verifiers must re-verify, and that invalid names are refused with a reason. These are exactly the side effects an agent needs before committing a rename.

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?

Information is front-loaded with the core action and format first, then consequences, then the caution. It is dense with five sentences, and the email re-verification note is somewhat peripheral, but every sentence contributes behavioral or constraint value rather than filler.

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 explained; the description instead covers the irreversible consequences, the format contract, and the pre-call confirmation rule. For a destructive, non-idempotent rename with just two required parameters, nothing an agent needs is missing.

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 100%, so formatting basics are already present, yet the description adds real constraints the schema omits: lowercase-only, digits and hyphens, and a 3-to-40 character length bound. This meaningfully reduces malformed calls beyond the schema's example-only guidance.

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 ('change the address a spawnpoint project is reached at') and immediately disambiguates the concept with 'the part before .spwt.app, e.g. lunch-orders'. This clearly separates it from siblings like share_project and add_custom_domain without requiring schema inspection.

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 a concrete when-to-consult-the-user rule ('Ask before renaming an app the user did not just make') and ties it to the consequence of already-sent links forwarding. It also advises keeping apps restricted when the address is guessable. It does not name sibling alternatives explicitly, so it falls short of a 5.

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