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

Goes well beyond the annotations by disclosing that each execution performs a live fetch of the Atlas dataset, that the call is paid (0.10 USDC on Base via x402 exact), that there is a shared quota of 10 free signed-wallet calls per rolling 30 days, and that X-Wever-Wallet-Proof binds the exact JSON args to the path. This is exactly the kind of cost/auth/quota behavior an agent needs and that readOnlyHint alone cannot convey. It stops short of describing failure or 402 retry behavior itself, deferring that to the endpoint contract.

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-loaded with purpose and return shape, then billing, which is the right priority order. The billing/permission paragraph is dense but every clause (price, quota, wallet proof, contract reference) carries actionable information, so there is little waste.

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-value burden and does so: seven named rows with value, detail and source identifiers, plus dataset version, catalog counts and retrieval evidence. Combined with the 402/contract pointer, an agent has enough to call it correctly, though edge-case behavior on invalid ids is left unstated.

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 coverage is 100% and both parameters already document id-or-ticker, case-insensitive matching. The description adds the same 'by id or ticker' framing but no extra semantics such as whether left/right ordering affects the output or how unknown tickers behave, so it is a baseline 3.

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 ('Compare two Atlas assets by id or ticker') and immediately enumerates the seven comparison dimensions returned, which distinguishes it from siblings like atlas-asset-passport and atlas-rights-gap. An agent can tell exactly what this produces 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?

Usage is implied by the comparison framing and the note that it is 'read-only rights analysis', but the description never states when to prefer this over atlas-rights-gap or atlas-asset-passport, nor any exclusion such as same-asset comparison or unsupported ids. The pointer to /api/atlas-rights-contract and the 402 body helps with setup but not with tool selection.

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