get_transit_commute

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

With no annotations provided, the description carries the full burden and does well: it discloses real-time vs predicted traffic behavior, the default mode, multi-leg support, and a concrete return shape (up to 3 alternatives with duration, lines, transfers, walking time). It omits auth/permission requirements and rate limits, which is a minor gap rather than a critical one.

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?

Front-loaded with purpose, then usage, then capabilities and return values — a logical order. It is slightly padded ('commute, travel time, or exact travel times' is near-redundant), but every line still contributes information.

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-value detail is not strictly required, yet the description adds useful shape information anyway. Together with the fully documented schema, an agent has enough to invoke the tool correctly; only sibling disambiguation and auth expectations are 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?

Schema description coverage is 100%, so the schema already documents mode defaults, avoid_tolls scope, intermediates, and departure_time semantics — the description mostly restates these. The A→B→C example adds a little clarity but no new semantics beyond what the schema supplies, 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?

States a specific verb and resource ('returns commute routes between two addresses') and names the underlying data source and supported modes. It is clear what the tool does, but it never distinguishes itself from the sibling compare_commutes, which an agent could plausibly reach for on the same query.

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 trigger conditions ('user asks about commute, travel time, or exact travel times between two addresses'), which is solid when-to-use guidance. It offers no when-not-to-use and does not name compare_commutes as the alternative for multi-address comparison, leaving that routing decision to inference.

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