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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered elsewhere. The description still adds genuinely new behavior: the NOT_FOUND outcome for an unknown id and the fact that only public fields (description, address, phone, website, hours, FAQ, photos) are exposed. It does not mention rate limits or pagination, which is a minor gap for a single-record fetch.

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 tight sentences, front-loaded with the read-only/single-record scope before the detail list. No filler, and the trailing error case is the last and least important clause.

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?

There is no output schema, but the description compensates by enumerating the returned public fields and the failure mode (NOT_FOUND), and annotations cover safety. For a one-parameter read tool, an agent has everything needed to call it correctly.

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% for the single id parameter, so the baseline would be 3. The description goes beyond the schema by stating a slug is also accepted as an identifier and by pointing at the originating tool, information the schema's 'Listing id from search_listings' does not convey.

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 (get) and resource (one 1-800Deals listing) with explicit scope ('one ... by the id'), and clarifies it is the detail counterpart to the search tool. It enumerates exactly which fields are returned, so an agent can distinguish it from search_listings and list_categories without opening a 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?

It tells the agent where the argument comes from ('the id from search_listings'), effectively establishing this as the follow-up call after a search. It does not state a when-not case or a true alternative, but for a leaf lookup tool the usage context is clear enough.

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