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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds non-annotation context the agent needs: the tool requires the user's Cotlet API key with access to this app, and it discloses the payload surface (viewing times, bidding status). It does not mention rate limits or pagination, but for a single-item read this is solid.

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 tool name is front-loaded and the usage instruction lands in the third sentence, but sentences one and two largely restate the same field list ('price, monthly fee, area, rooms... broker' then 'asking price, monthly fee, rooms, living area, the broker...'), which is redundant rather than additive.

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 burden of describing return values and does so adequately, plus it covers the auth prerequisite. It is complete enough to invoke correctly, though the duplicated field list means the payload description is verbose without adding precision.

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 listing_id parameter already documents its source ('Listing ID from search_listings or list_saved_homes'). The description adds no further meaning about the identifier, so the baseline 3 applies.

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+resource ('Get listing' / 'Returns one listing') and enumerates the content returned (price, monthly fee, rooms, area, viewing times, bidding status, broker). It clearly distinguishes itself from hemnet_search_listings by framing the tool as reading a single home in full.

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?

'Use it after search_listings to read a home in full' gives explicit ordering and names the sibling that produces the required listing_id. It does not state when not to use it (e.g. versus list_saved_homes or list_followed_homes), so it stops short of a full routing rule.

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