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

Adds meaningful behavior beyond the annotations: the auth requirement and its two forms, the fact that a claim accepts the free license and the result reports which version, and that only domain plus app id are persisted. The 'safe to repeat, returns the same result' line largely restates idempotentHint=true, so it is additive but not fully independent of annotations.

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?

Purpose is front-loaded in the first clause, and each subsequent sentence carries a distinct fact (auth, idempotency, limitation, optional param). It is six sentences and slightly sprawling, but no sentence is 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?

For a non-destructive, idempotent mutation with no output schema, the description covers the auth path, the repeated-call behavior, the rejected case, and the fact that the response reports the licensed version. Nothing an agent needs in order to call it correctly 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 the baseline is 3; the description earns slightly more by explaining what site_domain is for ('record which site will run it') and clarifying that only the domain and app id are stored. The app/app_id alias pair is explained in the schema rather than the description.

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: 'Add a free app (like Forms) to the owner's account', plus the key scope limit 'Paid apps can't be claimed'. That implicitly separates it from checkout/purchase siblings like create_checkout, but no sibling is named explicitly.

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 clear preconditions (owner signed in via browser sign-in, or an API key with the download permission) and an exclusion (paid apps cannot be claimed). It does not name an alternative tool to use when the app is paid, so no explicit routing.

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