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

No annotations exist, so the description carries the full burden. It does disclose a genuinely useful behavioral trait — 'Updated monthly' — and spells out the returned metrics, which tells the agent this is a low-risk read with a defined payload. It omits data source, currency/units, rank methodology, and whether small zips are suppressed, which for an unannotated tool keeps it at a middling score.

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?

Two tightly packed sentences with no filler: the intent question comes first, then the payload breakdown. Slightly indirect as an opening versus a direct verb statement, but nothing is wasted and it is easy to scan.

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 simple two-parameter read tool with full schema coverage and no output schema, the description supplies enough: what is returned, what the metrics mean, and how fresh the data is. Remaining gaps (units, rank methodology, behavior on invalid zip) are minor at this complexity level.

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%, covering both zip (5-digit pattern) and months (2-24, default 12), so the baseline is 3. The description's mention of '3-month rent growth' ranking hints at a window different from the months parameter, but it never clarifies how months interacts with the reported history or the rank window.

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 names a specific resource (monthly median-rent history for a zip) and enumerates what comes back: home values, direction of movement, and national/state rank on 3-month rent growth. That is far more concrete than the title alone. It does not, however, distinguish itself from the overlapping sibling get_zip_market, so an agent must infer the boundary.

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 opening question frames the use case (you want to know which direction rent is moving), which implies when to call it. There is no explicit when-not guidance and get_zip_market / compare_zips are never mentioned, even though they plausibly overlap on zip-level rent data.

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