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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's real contribution is the host-environment dependency (needs a UI-capable host) and the fact that the rendered view embeds a request form and a payment button, which implies side effects are surfaced here via sibling tools. It stops short of saying what happens on a non-UI host or whether the embedded form/payment button itself mutates state, which is the one ambiguity given readOnlyHint=true.

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 action, then the sibling comparison, then the routing preference. No filler and no repetition of the title.

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 an output schema present, the description doesn't need to explain return values, and it does cover the host requirement and tool-selection rule well. The remaining gap is the three undocumented parameters, which leaves an agent guessing about filtering inputs for a picker tool.

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?

Only 2 of 5 parameters (date, venue) carry schema descriptions, so coverage is 40% and the description compensates with nothing — zone, party, and max_min_spend are undocumented in both places. The description does hint that "venue" may accept an event name, but that detail already lives in the schema, so no net additive value for parameters.

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 ("Render") plus specific resource ("the interactive table picker for a venue and night") and a scope qualifier (ChatGPT / MCP Apps hosts). It also distinguishes itself from the sibling tool by noting it carries the same data as check_availability, so an agent can differentiate the two 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?

Explicit routing rule: "Prefer this over check_availability when the host can display UI." That names the alternative and the deciding condition, which is exactly what an agent needs to choose between two highly overlapping tools.

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