Compare offers

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

Annotations declare readOnly, idempotent, non-destructive, so safety is covered. The description adds meaningful behavior beyond that: it discloses that unknown eligibility and unsupported stacking are surfaced explicitly rather than silently resolved, which tells the agent how to interpret results.

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?

A single dense sentence with no filler, front-loading the verb and resource followed by the compared dimensions. Slightly overstuffed but every clause contributes.

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?

An output schema exists and annotations cover the safety profile, so return values need not be described. The description covers scope, compared dimensions, and the explicit-unknowns behavior, leaving little an agent needs missing.

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 100%, so both the offers array and the facts object are documented in the schema itself. The description's 'two to ten' restates minItems/maxItems and adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 (compare) and resource (two to ten startup credit or deal offers) side by side, and enumerates the dimensions compared (value, access requirements, eligibility, freshness, evidence). This clearly separates it from the sibling search_offers, which retrieves rather than compares.

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?

The comparison framing implies when to use it, but there is no explicit when-to-use/when-not guidance or named alternative (e.g., search_offers for lookups). Usage must be inferred from the tool name and verb.

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