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

Annotations already declare destructiveHint=true and idempotentHint=true, yet the description adds the specific destructive mechanism an agent actually needs: fields named but absent from the payload are CLEARED and nested objects are replaced wholesale rather than merged. That is exactly the kind of non-obvious write semantics 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?

Three sentences, zero filler, and the highest-risk information (the clear-and-replace semantics of `fields`) is front-loaded right after the purpose statement. The prerequisite read and the sibling exclusions are compressed into single clauses.

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 14-parameter mutation with no output schema and an openWorld profile, the description covers the destructive mechanics, the read-first workflow, and sibling boundaries well. It stops short of describing what the response returns or the permission/auth requirements for the update, which would complete the picture.

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 baseline is 3, but the description adds real meaning to the `fields` parameter by defining it as an exact replacement manifest with clear-on-omission behavior, which the schema's own 'Which fields to replace' text only implies. Other parameters (title, labels, openInfo, etc.) are left entirely to the schema.

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 ('Update fields on a Google Business Profile location') and explicitly carves out scope by naming siblings that own other parts of the resource ('Hours and the service list have their own tools'). An agent can distinguish this from google_business_hours_update and google_business_service_list_update immediately.

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 prerequisite flow ('Read with google_business_location_get first') and names two categories of fields that must not be routed here because dedicated tools exist. It does not mention the adjacent google_business_attributes_update, so the alternative-routing advice is strong but not exhaustive.

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