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

No annotations are provided, so the description must carry the full behavioral burden. It discloses that the call is free and points to a paid alternative, but it says nothing about authentication, rate limits, side effects, or the shape of the returned quote.

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?

The description is short, but the second and third fragments are syntactically broken and rely on unexplained jargon ('unpaid-fetch,' 'the probe') plus an inline install URL. The clear part ('Free quote only') is front-loaded, but the remaining text does not read cleanly or earn its place for selection.

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 tool with no output schema and no annotations, the description should at least explain what a quote is and what it returns. It does neither, and the mention of an install URL for a separate paid flow adds confusion rather than completeness.

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 no parameter information for the description to add. Per the rubric, a zero-parameter schema warrants a baseline of 4.

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 states 'Free quote only,' which gives a resource (quote) and a distinguishing condition (free), and it contrasts with the sibling token_snapshot. However, it never says what a quote contains or what domain it covers, leaving the purpose vague beyond the name and cost distinction.

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 names an alternative (token_snapshot) and a condition (paying agents), and adds an exclusion ('Not the probe,' though 'probe' is not a listed sibling). The garbled phrasing 'Paying agents unpaid-fetch token_snapshot $0.02' makes the routing condition ambiguous, so the guidance is only partially actionable.

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