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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds no additional behavioral context such as output structure, data sources, or side effects; it mostly restates the tool's purpose without contradicting the annotations.

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 concise sentences with no filler: the first states the core function, and the second adds important selection guidance by labeling the tool as the default multimodal option. Frontal loading is effective.

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?

The schema is detailed, output schema exists, and annotations cover the safety profile, so the description does not need to explain return values or side effects. The only minor gap is that it does not explicitly route the agent to single-mode siblings, but the sibling list and 'multimodal' language make that omission non-critical.

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 100%, with pickup and destination documented as 'Resolved pickup place' and 'Resolved destination place' and lat/lng ranges explained. The description adds no parameter-level meaning beyond what the schema already provides, so the baseline of 3 applies.

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 uses a specific verb plus resource: 'Compare ride-hailing and trotro options together.' It clearly identifies the tool as the multimodal trip planner and distinguishes it from siblings like compare_rides and plan_trotro_route, which are single-mode alternatives.

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?

The phrase 'This is the default tool for multimodal trip planning' gives clear context for when to choose it, especially relative to single-mode siblings. However, it does not explicitly state when not to use it or name the alternatives for ride-hailing-only or trotro-only requests.

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