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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds behavioral context: ranking by active listings, returning up to 10 agencies, and including a public URL. It doesn't mention pagination or sorting details beyond ranking, but the added context is meaningful and non-contradictory.

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?

The description is concise and well-structured: it states the purpose, the ranking logic, the return fields, and the usage context in three sentences. Every sentence earns its place, and the most important information (what it does) is front-loaded.

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 read-only list tool with two parameters and no output schema, the description is largely complete. It covers what the tool returns (name, location, listing count, URL), the ranking criterion, and the usage context. The only minor gap is the lack of explicit mention of the 'limit' parameter's behavior, but the description's 'up to 10' partially covers it. Given the tool's simplicity, this is adequate.

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 50%: 'location' is described in the schema, but 'limit' is not. The description mentions 'up to 10 agencies' which implies the limit parameter's effect, but doesn't explicitly explain the limit parameter or its default/maximum. The description adds some meaning beyond the schema (ranking, return fields) but doesn't fully compensate for the undocumented 'limit' 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?

The description clearly states the tool's function: finding PropertyList agencies in a Spanish area, ranked by active listing count. It specifies the resource (agencies), the action (list/find), and the context (Spanish area), which distinguishes it from sibling tools like search_properties or find_contacts.

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?

The description provides clear usage context: 'Use this after a buyer has narrowed in on an area and wants to know which agencies dominate it.' This implies when to use it, though it doesn't explicitly mention alternatives or when not to use it. The context is strong enough for an agent to select it appropriately.

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