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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior, so the description does not need to repeat those. It adds genuinely useful interpretation: 'Compare recorded values only; UNKNOWN does not mean an amenity is absent,' which clarifies how to treat missing data.

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?

The description is two sentences with no filler. It front-loads the usage condition and then adds the most important interpretive caveat, so every sentence earns its place.

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 safety and idempotence, an output schema covering return shape, and schema constraints covering slug count, the description supplies the remaining necessary context: when to use the tool and how to interpret UNKNOWN values. No significant gap remains for an agent deciding whether and how to call it.

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 0%, so the description must compensate for the single 'slugs' parameter. It does so by explaining that slugs are property slugs already found in search, must be distinct, and number between two and four. This, combined with the schema's min/max constraints, is sufficient for correct invocation.

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 uses a specific verb ('comparing') and resource ('property slugs') with a clear scope constraint ('two to four distinct'). This distinguishes it from siblings such as get_property_by_slug, which handles a single property, and search_properties, which is about discovery rather than comparison.

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?

It explicitly says 'Use this when comparing two to four distinct property slugs already found in search,' which gives clear context for when to call it. It does not explicitly list when-not-to-use or name alternatives, but the stated condition is enough to route the agent appropriately.

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