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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing the underlying operation ('OPTIONS /properties') and, critically in the absence of an output schema, enumerating what the response contains. It still says nothing about auth/permissions or rate limits on a live MLS feed.

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 short fragments with no filler, and the core content (what values are available) is front-loaded. 'OPTIONS /properties' is a slightly implementation-flavored trailing detail but is compact and informative.

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 no output schema, the description carries the return-value burden and does so by enumerating the metadata categories plus the last sync time. The main omission is that it never signals the vendor argument matters on multi-MLS apps, though the schema covers that.

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% and the single vendor parameter is fully documented there, including the multi-MLS requirement, so baseline 3 applies. The description makes no reference to the vendor parameter at all, adding no semantics beyond the schema.

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 specific resource (MLS feed metadata) and enumerates exactly what it contains — statuses, property types, cities, counties, neighborhoods, areas, features, and last sync time — which clearly separates it from siblings like simplyrets_search_listings or simplyrets_get_listing. It is a noun phrase rather than an explicit verb+resource, but the intent is unambiguous.

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 phrase 'to build valid searches' implies the intended use — fetch allowable values before constructing a search — but it never states when-not to use this tool or names an alternative among the nine siblings. Usage is inferable rather than spelled out.

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