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 genuine value beyond that: the shape of the returned data (collections with home counts and shared-with people) and the API-key authorization requirement, which annotations cannot convey.

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?

Three sentences, front-loaded with the resource and scope. There is mild redundancy, since "with who they are shared with" and "the people each is shared with" restate the same returned field, but the trigger and auth note are compact.

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 returns, and it does so (collections, home counts, sharees). Auth requirements and downstream usage are covered. Minor gap: it never states that the call is unfiltered/unpaginated, though for a zero-parameter list tool this is a small omission.

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?

The tool takes zero parameters, so the baseline is 4. The description correctly does not invent parameter semantics; its mention of collection_id refers to output consumed by sibling tools, not an input here, which could be mildly confusing but is framed as downstream usage.

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: listing the user's collections of saved homes, and immediately notes the distinguishing content (home counts and sharing info) versus a plain list of homes. It does not explicitly contrast itself with the closely named sibling hemnet_list_saved_homes, so it falls just short of a 5.

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 actionable downstream context: "Use collection_id with list_saved_homes and save_home" tells the agent how this tool's output feeds other tools, and names the auth prerequisite (Cotlet API key with app access). It lacks explicit when-not-to-use guidance but the usage context is clear.

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