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

Annotations already declare readOnly/destructive/openWorld, so the safety profile is covered. The description adds real context beyond that: the exact status vocabulary (for_sale, bidding, sold), that sold homes carry a final price, and that a Cotlet API key with app access is required.

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?

Front-loaded with what the tool returns, then the filter, then the auth requirement. Slight redundancy in 'Returns the homes in your saved homes' re-stating the opening sentence, but overall tight.

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 usefully characterizes the return shape (homes plus their collection, status, and final price) and the auth precondition. An agent has enough to call and interpret it; only the sibling-routing guidance is missing.

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 schema already explains collection_id including its source (list_collections). The description restates the filtering behavior without adding format or syntax the schema lacks, so 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 ('Homes you saved') and enumerates the returned fields (collection, status, final price). It is distinguishable from siblings like hemnet_list_followed_homes only implicitly, but the scope 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?

'Pass collection_id to see one collection only' gives a usage condition for the optional filter, and the API-key requirement is noted. However, there is no explicit guidance on when to prefer this over hemnet_list_followed_homes or hemnet_list_collections.

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