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 context beyond that by enumerating the detail sections returned (address, geo, price, photos, agent, office, property, school, tax, remarks) and identifying the underlying endpoint, letting an agent judge whether a call is worth making.

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 tight sentences with the identifier disambiguation front-loaded before the payload inventory, and the endpoint appended as a compact anchor. Every clause carries information; nothing is restated from the name or title.

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 compensates by naming the returned data categories, and it correctly notes the include extras are conditional on feed availability. It does not address failure behavior for an unknown or foreign id, which is the one remaining gap for a lookup tool.

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%, so the baseline is 3; the description exceeds it by clarifying that mlsId is the search-result number and explicitly NOT the public listingId, which prevents a plausible and costly misinvocation. It says nothing additional about vendor or include, which the schema already covers.

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?

States a specific verb and resource (one listing by its SimplyRETS id) and immediately pins the exact identifier semantics, which is the real source of confusion in this domain. The trailing GET /properties/{mlsId} makes the retrieval contract unambiguous and clearly separates it from simplyrets_search_listings.

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?

Gives clear context for use: fetch full detail for a single known listing, with the disambiguation that mlsId is the number in search results while listingId is the public MLS number. It never explicitly names simplyrets_search_listings as the way to obtain that mlsId, so routing is inferred rather than stated.

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