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

With no annotations, the description carries the full burden and does well on the highest-stakes trait: cost ($0.015 USDC on Base), the 402 PAYMENT-REQUIRED challenge shape (amount, asset, address), and the free-with-API-key path. It is silent on what happens for a non-existent pair, rate limits, and the default sample size of 8, which is a meaningful omission for an unannotated paid endpoint.

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?

Good front-loading with the payload description first and the payment/routing information last, but the middle paragraph contains rhetorical filler ('a number nobody argued with', 'not an appendix') that informs a human reader more than an agent. The payment paragraph, by contrast, earns every sentence.

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?

There is no output schema and no annotations, so the description must do more work than it does. It describes the conceptual return content well, but leaves the two required identifiers' format, error behavior for unknown pairs, and the default sample size unexplained, which are exactly the details an agent needs to invoke this correctly.

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% and all three parameters (source, target, limit) are undocumented. The description never says whether source/target take framework IDs, slugs, or names, nor does it name or bound the limit parameter beyond loosely implying that samples are returned. Only a faint hint about sampling partly compensates for the coverage gap.

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 first sentence names the exact resource and scope: one crosswalk pair in full, explicitly including rejected claims. It then enumerates the payload (coverage percentage, sample of held claims with reasoning, sample of refuted claims with failure reasons) and differentiates itself from the free list/search/get siblings. An agent can tell what this returns without opening the schema.

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 states the selection context clearly for the paid/free split: without payment the call returns 402, a Professional API key is served free, and it names three free alternatives (pair listing and framework catalogue lookups). What it does not do is contrast itself with the closely related siblings agent_crosswalk_refuted and agent_crosswalk_provenance, which overlap in subject matter.

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