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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds useful context beyond them: the listing is public (no auth implied) and the return payload is a full record with named sections. It does not say what happens on an invalid or stale key, which is the main remaining unknown.

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 sentences, front-loaded with the capability and followed by the input-source detail; nothing is padded. The trailing "/prona/... or the part after /prona/" is slightly repetitive but does clarify the accepted shorthand.

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 one-parameter read with annotations covering safety and no output schema, the description carries the necessary load by naming the returned fields and the input sources. Error behavior and whether listings are fetched live vs cached are the only notable omissions.

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% and the single parameter already documents both accepted forms (full URL or the key after /prona/). The description restates those same forms and adds the provenance hint (values come from search-listings), which is helpful but largely duplicative of the schema text.

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 ("Get one public listing in full") and enumerates what comes back (description, amenities, photos, year built). It is immediately distinguishable from search-listings, which returns multiple results rather than one full record.

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 ties usage to the sibling by saying the input comes "from search-listings or pelikani.net", which implies the find-then-fetch workflow. It lacks an explicit contrast statement such as "use search-listings when you don't already have a key", so the routing is inferred 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.