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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds genuinely useful context beyond that: results carry official sources, Jumbo classification is explained, and Spanish output has a specific disclosure-handling rule (legal text stays English verbatim with a courtesy translation).

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?

Front-loaded with the core resource and scope in the first clause, and no sentence is filler. The heavy parenthetical stacking (FHFA, Fannie Mae / Freddie Mac, HUD) makes it denser than necessary, slightly hurting readability.

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 annotations covering the safety profile and a fully documented schema, the description supplies the domain context an agent needs: what limits are returned, for which unit counts, for which geography, and in which language. With no output schema, it could say more about the return shape (e.g., per-unit-count conforming vs FHA figures), which is the one remaining gap.

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 coverage is 100%, so the baseline is 3; the schema already documents state, county slug format, and the language enum with its disclosure caveat. The description adds little parameter-level detail beyond restating that language=es yields Spanish and supplying the Spanish term 'límites de préstamo'.

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 the exact resource (2026 conforming FHFA/Fannie Mae/Freddie Mac and FHA/HUD loan limits), the unit range (1–4 units), and the geographic scope (a county CapCenter serves). It is unmistakably distinct from siblings like get_todays_rates, get_mortgage_quote, or get_affordability_estimate, and even defines the Jumbo threshold.

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 is implied by the scope statement ('in a county CapCenter serves') and the schema note that only licensed states are answered, but the description never says when to prefer this over alternatives or when not to call it. No sibling tool is named as an alternative for related questions.

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