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

Annotations already declare readOnly=true, idempotent=true, non-destructive, closed-world, so the safety profile is covered. The description still adds real context beyond them: it discloses the return shape ('sorted table with a short reason per row') and reinforces the informational/non-execution nature ('Information only'). It does not state behavior for missing/expired offers or how ties are broken.

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 the action and the ranking criteria, then the return shape, then the read-only note — every sentence earns a place. 'Information only. Read-only.' is slightly redundant with the readOnlyHint annotation, which keeps it from a 5.

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 3-parameter, no-output-schema tool, the description does the heavy lifting: it covers the required token, the ranking axes, the output shape, and safety. The gap is the undocumented `kind` filter and no note on default sort behavior or empty-result handling.

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%, so the description has to compensate. It does partially: the four named ranking dimensions map directly onto the sortBy enum values (premiumOverStrike, premiumPerToken, strikeVsSpot, expiry), giving meaning the schema lacks. But the `kind` (call/put) parameter is never mentioned, leaving one of three parameters unexplained in both structured fields and prose.

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?

Specific verb and resource: 'Rank the open offers on one token', followed by the four ranking dimensions and the return shape ('sorted table with a short reason per row'). An agent can tell this is an analysis/ranking tool rather than a lookup, though it never names a sibling (find_offers, explain_offer) to sharpen the boundary.

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 only implied: ranking implies you call it when you already have a token and want offers ordered against each other rather than listed or explained. There is no explicit when-to-use statement, no exclusion against find_offers or explain_offer, and no prerequisites beyond the token.

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