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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds behavioral value by enumerating what the response contains (progress count/quantity, in/out amounts, failed sub-swaps), which goes beyond the annotations. It does not address why idempotentHint is false for a read, nor return format/pagination.

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 sentence that is front-loaded with the core purpose and then enumerates the result fields without filler. Efficient, though the trailing field list makes it slightly dense.

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, so the description must carry the return-value burden, and it partially does by naming progress, amounts, and failed sub-swaps. For a single-parameter read tool this is nearly sufficient, with only pagination/format details absent.

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%, and the schema already documents the sole parameter as "the inbound transaction hash". The description's "by transaction hash" adds no syntax or format detail beyond that, 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 ("Returns details"), a specific resource ("streaming swap"), and the lookup key ("by transaction hash"). This distinguishes it implicitly from list_streaming_swaps, but the differentiator is only implied rather than named.

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 phrase "by transaction hash" implies the usage case (you already know the hash and want one swap's details), which is enough to separate it from the list variant. However, there is no explicit when-to-use guidance and no named alternative or exclusions.

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