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

With no annotations, the description carries the burden and it delivers: 'Read-only / idempotent; does not place trades' directly discloses safety and side-effect profile. It also reveals that full parameters are gated behind x402 and requires an unlock step. It stops short of discussing rate limits or data freshness, but the key behavioral traits are covered.

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, usage windows, exclusions, read-only status, parameter range, and the payment flow. The content is dense but organized, with the core purpose front-loaded. Minor punctuation/slash complexity costs a point, but it remains efficient.

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?

The description covers when, why, and how to invoke, plus the required x402 flow. The output schema presumably documents return fields, so not explaining return values is acceptable. The only slight gap is the ambiguity of 'the unlock URL in the response' – unclear whether it belongs to this tool or the payment challenge – but the overall flow is understandable.

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 0%, so the description must compensate. It provides a critical constraint not in the schema: '`limit` is 1–20.' For a single integer parameter with a default, this range is the main semantic gap, and the description fills it well.

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 opens with a precise statement: 'Return HMAC-committed SEC Form 8-K Item 2.01 M&A alpha teasers.' It names a specific verb, resource type, and qualifying detail. This clearly distinguishes it from the sibling tools (arbitrage spreads, velocity signals, x402 challenge).

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?

It explicitly states when to call ('Call after a material acquisition disclosure when you need teaser_id / proof_hash / entity metadata') and when not to call ('Do not call for Kalshi/Polymarket price arb or short-DTR velocity — those are separate tools'). It also provides a brief workflow for the x402 payment path.

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