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

Annotations already declare read-only/idempotent/open-world safety, and the description adds meaningful behavior on top: the API-key dependency, the failure mode when no close name match is returned, and an explicit anti-hallucination instruction. It does not describe return shape or rate limits, but the added context is genuine.

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?

Four short sentences, all front-loaded and free of padding. The staccato list of caveats reads slightly like a policy dump rather than a description, but nothing is wasted.

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?

No output schema exists and none is needed for a read-only lookup, and the description covers the key failure modes. But with a four-parameter schema at 25% coverage and no explanation of how the identifiers interact, an agent still lacks enough to invoke it confidently in ambiguous cases.

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 only 25% (just the 'example' fixture flag), yet the description explains none of name, yelpUrl, or location or how they relate (e.g., is yelpUrl an alternative to name+location?). With three of four parameters undocumented, the description fails to compensate for the coverage gap.

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?

Specific verb ('Fetch') plus resource ('a Yelp Fusion business'), and it explicitly scopes out TripAdvisor, which helps separate it from get_google_listing and get_website_profile among the siblings. It stops short of naming the sibling tools it competes with, so it is clear but not maximally differentiated.

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 gives a precondition (YELP_API_KEY must be set) and a fallback ('If the key is missing ... say so'), which is real usage context. However it never says when to prefer this over get_google_listing or find_restaurant, so the alternative-selection guidance is only implied.

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