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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, so safety is covered structurally. The description adds genuinely useful non-annotated context: no authentication/account needed, and the default-radius rule (exact city inventory for city/ZIP, 15 miles for landmarks), which materially affects how the agent should call it.

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?

Four sentences, each doing distinct work: capability, relevance, geo-default rules, and result content. Front-loaded with the core verb and resource; nothing is padded, though the final results sentence is partly redundant with the output schema.

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 7-parameter search tool with an output schema and full annotation coverage, the description supplies what's missing: account requirements, radius defaults, and care-type coverage. Return-value details are already in the output schema, so brevity there is appropriate; the only gap is the absence of explicit sibling routing.

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 71%, so the schema already documents most parameters including radius and coordinate semantics. The description nonetheless adds meaning by enumerating the resolvable destination forms (city, ZIP, hospital, neighborhood, landmark, verified coordinates) and by clarifying the radius default behavior in prose, reducing ambiguity for the required destination parameter.

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 ('Public, read-only search for senior living communities') plus the full set of location inputs it accepts, so the agent knows exactly what this tool does. Mentioning that results carry 'stable facility IDs' implicitly routes detail lookups to the sibling get_facility, giving de facto sibling differentiation.

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?

Explicitly frames the questions this tool answers (assisted living, memory care, independent living, 55+, other care types in or near a place) and states that no account is required, which is clear usage context. It does not explicitly name get_facility as the follow-up alternative for a single known facility, so routing guidance stops short of full when/when-not coverage.

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