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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false. The description adds two things the annotations cannot: the authentication requirement and the externally visible side effect (it persists into the user's saved searches on the web app). It stops short of explaining what happens when a name already exists, which is the key behavioral question for an idempotent save.

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 short sentences with no filler: identity of the operation first, equivalence to search_listings second, prerequisite last. Every clause earns its place and nothing is repeated from the schema.

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 16-parameter write tool with no output schema, the description covers purpose, persistence, auth and filter provenance, which is enough to call it correctly. It leaves open the duplicate-name/idempotency behavior and why a saved search carries a 'page' parameter, which are minor but real gaps.

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?

With 16 parameters at 81% schema description coverage, the schema carries most of the semantic load and the baseline would be 3. The description's 'same filters as search_listings' adds real value by telling the agent it can reuse a known filter vocabulary rather than re-deriving 16 fields, plus it hints at the naming intent via the 'save under a name' phrasing.

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 ('Save a search under a name') and locates the effect ('appears in the person's saved searches on evryroom.com'). It also differentiates from the sibling search_listings by clarifying that the same filters are reused rather than redefined, so an agent can distinguish saving from searching without opening either schema.

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 a clear prerequisite ('Needs sign-in') and implicitly routes the agent from search_listings (build the filters there, then save them here). It does not name an explicit when-not or point at my_saved_searches/delete_saved_search for managing existing saves, so the sibling routing is not fully spelled out.

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