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

Annotations already declare a safe read-only, idempotent, non-destructive profile, and the description adds genuinely non-obvious context on top: the data is crowdsourced from extension users and offers are account-targeted, with the explicit caveat that a listed card means several users saw it rather than every cardholder having it. That provenance and targeting nuance is exactly the kind of behavioral disclosure the schema and annotations cannot carry.

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, front-loaded with what the tool returns, then filtering and the caveat. The first sentence is dense but every clause carries information; nothing is padding.

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 usefully enumerates the returned fields and covers the zero-filter default. It omits the limit/pagination behavior, which matters given a default of 20 and a max of 50, keeping it just under fully complete.

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 67%, and the description's filter list broadly maps to the existing parameters but adds no meaning beyond them (e.g., no syntax for card or merchant strings, no note on limit). Baseline 3 is appropriate where the schema already documents most inputs.

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 (search) and resource (card-linked Amex Offers / Chase Offers), plus the scope qualifier 'live today' and the exact fields returned. This cleanly separates it from siblings like search_cashback_portals and list_credits, which cover different instruments.

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?

Explains the filter surface (issuer, merchant, card, expiry window, popularity) and explicitly states the fallback behavior: 'with no filters it returns an overview.' It gives clear usage context but never names a sibling tool or an exclusion condition, so it stops short of the 5 bar.

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