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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and non-open-world, so the safety profile is covered. The description adds real contract detail beyond that: the [{tripRef, summary}] shape, the 15–30 word differentiating-line rule, and the omission rule for non-differentiating entries.

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Two sentences, front-loaded with the most decision-relevant fact (legacy/superseded), then the payload contract. Dense but each clause carries weight; no filler.

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?

An output schema exists, so return values need not be described, and the description covers lifecycle status, payload format, and omission behavior. For a legacy passthrough helper this is nearly sufficient; the only gap is the semantics of the echoed inputs.

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 0% with 6 parameters, so the description carries the burden. It names the echoed fields (search/buses/currency/followups/disclaimer) and documents the required summaries array's item structure, which the schema leaves as opaque additionalProperties. It still doesn't clarify the meaning or defaults of the echoed fields.

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?

The description identifies a specific verb+resource and, unusually, states its lifecycle status ('Legacy, app-only helper superseded by the widget's get_bus_ai_summaries path'), which lets an agent distinguish it from siblings. The mechanism of 'apply' (what actually happens when summaries are applied) is still a bit opaque, keeping it below a 5.

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 explicitly names the superseding alternative (get_bus_ai_summaries) and tells the agent this is app-only, has no UI template, and is not a chat tool, which is effective when-not guidance. It stops short of stating any condition under which this tool is the correct choice, so a 4 rather than a 5.

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