cost_routing_explain

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

With no annotations, the description carries the behavioral burden. It clearly discloses the return type (human-readable explanation) and its content (provider and rationale), and the verb 'explain' implies no state mutation. It does not mention rate limits or cost effects, but those are less critical for an explain-style tool.

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?

The description is compact, front-loads the tool's purpose, and avoids unnecessary detail. Every clause earns its place.

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 single-parameter explain tool, the description sufficiently covers the input and the return value, with no output schema to duplicate. The only notable omission is guidance relative to cost_routing_stats, which is already accounted for under usage_guidelines.

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 the category parameter and its allowed values. The description adds no additional parameter-level meaning beyond framing it as a memory category, so the baseline score of 3 is appropriate.

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 action ('explain') and resource ('routing decision for a memory category') and states the output: which provider will be used and why. It is clear, though it does not explicitly differentiate itself from the sibling cost_routing_stats.

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 intended usage is implied: use when a human-readable explanation of a routing decision is needed. However, there is no explicit when-to-use/when-not-to-use guidance or mention of alternatives such as cost_routing_stats.

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