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

Goes well beyond the annotations (readOnly=false, openWorld=true, destructive=false): it discloses the required owner privilege, the 100 non-owner-user limit, that the action reaches other people and should be confirmed, the per-call confirmation default, and the Cotlet API key requirement. This is exactly the extra behavioral context the lower annotation bar rewards.

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?

Front-loaded with the core action and constraints, but it repeats the permission levels twice ('as owner, full or restricted user' then again 'Permission is owner (a delegated owner), full or restricted'), and the confirmation/API-key notes read as bolted-on rather than integrated.

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 mutation tool with no output schema and openWorld behavior, the description supplies the privilege requirements, quota limit, input restrictions, and confirmation expectations an agent needs to invoke it safely. Nothing critical 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 already 100%, so the baseline is 3, but the description adds real nuance: 'owner (a delegated owner)', that email must be a valid Google Account, and that an email group cannot be added — constraints not present in the schema descriptions.

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 (add) and resource (user to a Search Console property) with the permission levels involved. An agent can distinguish it from the sibling google-search-console_remove_user and google-search-console_list_users without opening the 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 strong prerequisites ('Owners only', 'You must be an owner of the property, or of its parent property') and constraints (100 non-owner user cap, no email groups), and instructs confirming with the user before each call. It does not explicitly name the alternative tools for the inverse operation, but the when-to-use context is clear.

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