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

Goes well beyond the annotations by disclosing the billing model (no charge here, charge only if the run passes controls), the two built-in controls (competition as filer denominator, shrinkflation must be 0), the presence of stated limits and a run id, and the dated citation line. This is consistent with readOnlyHint=true since the tool performs no mutation and incurs no cost.

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?

Front-loads the deliverable and the no-charge behavior, then the payment mechanics, with no filler sentences. Density is high and jargon like MPP and 'shrinkflation' is used without definition, which costs a bit of readability.

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, the description carries the return-shape burden and does so: payment_url, price, instructions, run id, and citation line. For a three-parameter quoting tool, everything an agent needs to call it and act on the result is present.

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%, with start, end, and phrase already fully documented including defaults, bounds, and an example. The description adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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: measures what share of U.S. 10-K filers mention a phrase year by year from SEC EDGAR full-text search, and clarifies this specific tool only validates the request rather than running anything. The 10-K/phrase framing clearly separates it from sibling trend tools such as run_regulatory_trend, run_spend_trend, and run_ai_visibility.

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 explicit operational guidance for the follow-up step: the tool charges nothing, returns a payment_url, and payment is made by POSTing over MPP with an HTTP 402 and a Stripe shared payment token. What's missing is explicit routing guidance against siblings (e.g., when to pick this over run_regulatory_trend or run_triangulation), which the agent must infer from the 10-K domain.

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