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

With no annotations, the description carries the full burden and does so well: one-minute polling cadence, single-fire behavior, HMAC-SHA256 signing with the exact header format and key source, TTL defaults/bounds, and a per-call cost with payment protocol. This is far beyond what a bare name implies.

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?

Purpose is front-loaded in the first clause, followed by tightly packed operational details. The signing sentence is dense but each clause carries non-redundant information; nothing is wasted.

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 and no annotations, yet the description covers firing behavior, signing, TTL, cost, and status-check path. It stops short of describing the event payload shape or webhook retry/failure behavior, which an agent might want.

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 low (40%), so the description must compensate, and it adds the ttl_hours default (168) and the webhook_url signing contract. price/direction/symbol semantics remain unelaborated, though they are largely self-evident from the enum and type.

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 ('Arm a price trigger with webhook delivery') plus the mechanism (polling + signed POST). It also distinguishes itself from the sibling get_trigger_status by noting status checks are free at a separate endpoint.

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 clear operational context: single-fire semantics, first-crossing-only firing, and where to check status instead of re-arming. It does not explicitly state when arming is inappropriate or contrast with any other arming alternative.

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