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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower, and the description still adds real substance: results are described as including asking rents, verification dates, and source links, which substitutes for the absent output schema. It is silent on pagination behavior and defaults for limit/offset, which is the main remaining gap.

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?

Five short sentences, zero filler, front-loaded with purpose before input rules and result contents. Each sentence adds a distinct fact (what it finds, how to address it, constraint, ID guidance, return fields).

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 10-parameter search tool with no output schema and near-zero schema descriptions, the definition covers input addressing and output fields reasonably well. But pagination, the meaning of limit/offset, and the bedrooms filter are never addressed, so an agent still has to guess at several call-shaping details.

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 only 10% across 10 parameters, so the description carries heavy burden and does partially compensate: it clarifies that a property name goes in query, that neighborhood depends on city, and that rents have an ordering constraint. However, limit, offset, bedrooms, and the ZIP format receive no explanation anywhere, leaving a third of the parameters undocumented end to end.

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?

"Find last-verified apartment listings" gives a specific verb and resource, and the mention of multiple building names matching plus returned IDs signals this is a search/list tool rather than a detail fetch like get_property. It stops short of naming a sibling explicitly, so the boundary with get_property or get_market_stats is inferable but not stated.

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 gives concrete invocation conditions: supply a city, state, ZIP, or property name, and a neighborhood requires its city. It also sets an input constraint (min_rent must not exceed max_rent) and a follow-up rule (use returned IDs when multiple buildings match). It offers no explicit when-not guidance or named alternative tool.

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