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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the description's job is to add context — and it does: cost of 2 credits per successful call, zero cost on 404/401/402 failures, first-party data source, and a ~24h cache TTL tied to property record refreshes. This is exactly the operational detail an agent cannot get from structured fields.

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?

Markdown headers front-load the most important section (what it returns), followed by usage, pricing, and a one-question FAQ that carries genuinely non-redundant freshness information. Every section earns its place and 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 an output schema present, the description needn't enumerate return fields and still names the key one. For a single-parameter read tool it covers purpose, use cases, cost, failure-cost behavior, and data staleness — nothing material an agent needs is missing.

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% for the single `property_address` parameter, including format and an example, so the schema carries the semantics. The description adds no additional guidance about address formatting, normalization, or what happens with ambiguous addresses, so baseline 3 applies.

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: returns the current Homesage.ai AVM estimate for a US residential property as a single point value, and even names the return field (`current_value`) inside an `Estimates` object. The word "current" implicitly contrasts with the history/other-value siblings, but no sibling is named explicitly, so an agent must infer that `get_home_value_history` is the alternative for trends.

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?

A dedicated "When to use it" section gives two concrete scenarios: setting a listing price and triggering threshold alerts on AVM movement. That is clear contextual guidance, but there are no exclusions or named alternatives (e.g., when to prefer `get_full_report` or `get_home_value_history` instead), which keeps it short of a 5.

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