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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds substantive behavior beyond that: the estimate is explicitly not an appraisal and carries an as-of date and disclaimer, three ordered next-step links are returned, Spanish responses keep legal disclosures verbatim in English, and mortgage_balance is never stored.

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?

Purpose and scope are front-loaded in the opening clause, and each subsequent element (as-of date, disclaimer, next-step links, language, mortgage_balance) is load-bearing. It is a single heavily nested sentence, which makes it denser than it needs to be, but there is no filler.

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?

With no output schema, the description does the work of describing the return payload: the three value bands, as-of date, disclaimer, and the ordered next-step links. Combined with the licensing constraint, language behavior, and optional mortgage_balance handling, an agent has everything needed to call it correctly; only error/not-found behavior is left implicit.

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%, so baseline is 3; the schema already explains address vs listing_url, the en/es enum, and the mortgage_balance rounding behavior. The description contributes modest extra meaning, chiefly the 'valor de la vivienda' Spanish phrasing and the address-or-URL choice, but nothing the schema does not already say.

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: an automated home value estimate with low/median/high bands, for either a street address or a capcenter.com listing URL. It is clearly not the same thing as the affordability, savings, or rate siblings, but it never names or contrasts those tools explicitly.

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?

Usage context is implied rather than spelled out: coverage is limited to states where CapCenter is licensed, and inputs may be an address or a listing URL. There is no explicit when-to-use / when-not-to-use framing against siblings such as get_affordability_estimate or search_homes_for_sale, so the agent must infer routing.

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