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

Annotations cover the safety basics (readOnlyHint=false, destructiveHint=false), and the description adds genuinely new behavioral context: the default non-overwrite policy, a $0.15 per-call cost, and an API-key requirement. It does not describe rate limiting, failure modes when Google has no match, or interaction between place_id and business_contact_id; note also that openWorldHint=false sits uneasily with a documented external Google API dependency.

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 tight clauses: what it fills, the non-overwrite default, and the cost/auth note. Nothing is redundant, though the parenthetical field list and price note are packed densely into one sentence rather than separated for scanning.

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 described. However, with five parameters and zero required, the definition should say which identifier (place_id or business_contact_id) the caller must supply and what happens if neither is given; that gap leaves the agent unable to construct a valid call from the description alone.

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 description coverage is only 40% (request_id and idempotency_key are documented; place_id, fill_empty_only, business_contact_id are not). The description compensates partially by stating the default for fill_empty_only, but it never explains the role of place_id versus business_contact_id or whether either is required.

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?

The description names a specific verb and resource ('enrich ... saved place card') plus the fields it fills (hours/address/phone/website) and the external source (Google Places). This clearly separates it from sibling mutators like update_place, which edit a place card without an external data source.

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?

It gives clear context for use: it is 'optional', defaults to non-overwriting behavior ('fill_empty_only — does not overwrite agent-supplied fields'), and carries a cost/auth requirement. It does not explicitly name alternative tools (e.g., update_place) or state when to prefer manual editing, so it stops short of full when/when-not guidance.

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