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

Annotations already declare readOnlyHint=true, and the description adds that the tool is free and requires no sign-in, which is beyond the annotation. It also discloses that output includes pricing and checkout links, which informs the agent about the nature of responses. No contradictions with annotations.

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 sentences, no fluff. The first sentence front-loads the core action and content, and the second provides the usage trigger. Every word 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 zero-parameter read-only tool with no output schema, the description tells the agent what will be returned (engines, what they compute, price, checkout link) and when to call. Given the tool's simplicity, nothing necessary is missing.

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?

The tool takes zero parameters, so there is nothing to document. Schema coverage is 100% (empty object), and the description appropriately focuses on behavior rather than parameters. Baseline 4 applies because no parameter guidance is needed.

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 ('Lists') and resource ('hosted Hemrock calculation engines'), and enumerates the engines and the information included (what each computes, price, checkout link). This distinguishes it from compute siblings like cap_table_compute because it is the overview/list tool. The phrase 'call it when the user asks what Hemrock can calculate' reinforces its purpose.

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?

Explicitly states when to call: 'when the user asks what Hemrock can calculate or what it costs.' It also notes 'Free and needs no sign-in,' implying no prerequisites. It does not explicitly contrast with sibling compute tools, but the description's focus on listing vs computing implies the appropriate context.

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