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

With no annotations, the description must carry the full burden. It does disclose the +10% promo bonus, that it is capped, and that the ANANSI rail is disabled in v1 – real behavioral context. It omits auth requirements and what 'capped' means numerically, and gives no hint of the quote's shape.

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 short sentences, front-loaded with the core action and immediately followed by the material caveat. No filler, though it is arguably too terse for a tool with a disabled rail.

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?

No output schema exists, so the description could explain what a quote returns (rate, bonus, expiry), but does not. It also leaves unresolved what calling this actually yields given the rail is off in v1, which an agent needs to know before invoking.

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 only 50%: usd_amount has no description in either schema or description, and the description says nothing about units, minimums, or format. With low coverage the description should compensate, and it does not; only the api_key param is documented (in the schema).

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 (Quote) and resource (credit top-up paid in ANANSI), which is more than a restatement of the name. However, it does not differentiate from the very similar sibling 'quote_anansi', leaving an agent to guess which quoting tool applies.

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?

'Quote only: the ANANSI rail is OFF in v1' signals this is a read-only estimate and that the underlying rail is non-functional, which is useful context. It never states when to prefer this over quote_anansi or what to do instead while the rail is off.

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