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

No annotations exist, so the description carries the full burden. It discloses routing, failover behavior, and the route field's content (scoring, rejection reasons, missing credentials). It lacks detail on side effects, cost guarantees beyond max_cost_usd, or response structure, but the disclosed behavior is substantive.

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 deliver purpose, routing/failover behavior, and route semantics with zero filler. Key behavioral details are front-loaded.

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 no output schema and no annotations, the description explains the route field but omits the input/capability format, hedge semantics, and what output besides route is returned. An agent cannot reliably construct a valid call without additional inference.

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 coverage is 60% (only prefer and max_cost_usd have descriptions). The description adds no parameter-level details for capability, input, or hedge. The core capability argument is undefined, and input is an undocumented nested object, requiring the agent to guess their structure.

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?

'Run a capability' is a specific verb+resource and the routing/failover behavior distinguishes it from siblings, though it does not explicitly name alternatives or clarify how it differs from thruact_call.

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 description implies use when a capability needs execution with failover, but provides no explicit when-to-use vs alternatives or exclusions. It does not mention related tools like thruact_compare or thruact_proxy.

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