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

Beyond the readOnlyHint/idempotentHint annotations, the description discloses the key behavioral traits: this is an interactive UI panel requiring a user decision, missing start/finish render as empty fields, fields in routeSettings.ignoredFields are shown as not applied, and clicking Optimize yields a single-use confirmation token for route creation. The "single-use token" is a mild tension with idempotentHint but is framed consistently as a read operation; what remains undisclosed is what happens if the user cancels the panel.

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 what the panel does, then inputs, then the read-only/token consequence. Dense but every clause carries information; the long compound sentences slightly reduce scannability.

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?

For a nested-input tool with an output schema, the description covers the semantics an agent needs: input shape, empty-field behavior, ignoredFields rendering, and the token handoff to creation. Since an output schema exists, the return shape need not be restated; only dismissal/cancellation behavior is unaddressed.

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?

With 50% schema coverage, the description compensates meaningfully: it explains that each entry is an original address plus its suggested matches, that empty candidates become a re-search affordance, and that ignoredFields controls what is displayed as not applied. It adds no detail on roundTrip, distanceUnit, or timeAtStopMinutes, but those carry schema defaults and descriptions.

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?

"Shows a panel where the user picks a match for each address and sets the start, finish, time at each stop and distance unit" gives a concrete verb (shows a picker panel) and resource (address matches + route settings), which is clearly distinct from search_places or create_route. It stops short of naming a sibling as the alternative path, so the differentiation is inferred from the mention of route creation at the end rather than stated.

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?

Use context is implied rather than stated: the panel consumes "each original address with its suggested matches" and addresses lacking suggestions "let the user search again in the panel," which tells an agent this follows a place-search step. There is no explicit when-to-use/when-not guidance, and no statement about what the agent should do instead if it already has confirmed coordinates.

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