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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile needs no restating. The description earns credit for adding behavior the annotations cannot: result cap of 5, nearest-first ordering, an expiry date on the answer, and the 'dates change – always send people to the official site' freshness caveat.

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?

Dense but front-loaded: the use-case leads, the exclusions close, and each clause carries information. The return-shape enumeration ('the date we checked it, the date the answer stops being served and a link to our page') is slightly list-like and partially duplicates the output schema, costing a point.

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 annotations covering safety, a 100%-covered input schema, an output schema (so return values need no explanation), and now explicit freshness/expiry behavior and exclusions, an agent has everything needed to call this correctly against a single sibling.

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 coverage is 100%, so baseline is 3; the description goes beyond it by framing the kind choice as a binary switch ('Choose "light_displays" or "tree_farms"') and by tying start_date/end_date to the 2026 season. It does not restate radius or viewing semantics, which the schema already handles well.

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 twin resources ('where to see Christmas lights... or where to cut their own Christmas tree'), plus geographic scope (US city/state/ZIP) and season (2026). It explicitly names the sibling it is not ('find_christmas_markets covers those'), so an agent can route between the two 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?

Gives explicit when-to-use ('someone asks where to see... or cut their own tree... near a US city'), when-not-to-use (list every display, non-US places, tickets/lodging, Christmas markets), and the sibling alternative for the excluded case. Nothing is left to inference.

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