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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description adds value by disclosing scope restrictions (only Coimbatore/Chennai), the supported=false response for out-of-scope cities, and the need to surface scopeMessage. This goes beyond what annotations provide, though it doesn't detail the full output structure (covered by output schema).

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 three sentences, each earning its place: purpose, usage trigger, and scope/alternative handling. It is front-loaded and free of fluff, providing maximum information in a compact format.

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?

The description is complete for a comparison tool with rich schema and output schema. It covers the supported cities, the scope behavior, and the key alternative tool. Nothing essential is missing given the structured fields already provide parameter details and output schema.

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 100%, with each parameter already described in detail. The description adds minimal parameter-specific insight beyond mentioning '2–3 localities' which is already encoded in the schema's minItems/maxItems. It does not introduce new meaning for city or propertyType, so baseline 3 is appropriate.

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 compares 2–3 localities side-by-side with specific aspects (price trends, livability, investment grade, etc.) and names the cities (Coimbatore/Chennai). It explicitly distinguishes itself from compare_properties, making its purpose unambiguous and distinct from siblings.

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 explicit when-to-use guidance ('X vs Y' or 'which is better' for buying/renting) and an alternative (use compare_properties for listing comparisons). It also defines behavior for out-of-scope cities (return supported=false and surface scopeMessage), giving clear conditions for use.

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