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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description usefully adds that the response is 'Signed' and 'Facts only; SwapEazi moves no money', reinforcing that no state change or fund movement occurs. It also discloses the scope of the returned history ('every day since it was kept'). It does not cover error behavior such as an unknown or expired intent_id, which is the main remaining gap.

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?

It is a single front-loaded sentence with no filler, and the resource comes first. But the middle clause ('what paying now, locking the rate and holding unhedged need') is ungrammatical and forces re-reading, and the closing 'Facts only; SwapEazi moves no money' is good but tacked on after the main content.

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 carries the burden of describing the return value, and it does so reasonably well by enumerating the tracked fields (route, cost of paying today, lock-at level, due date, changes over time). For a single-parameter read tool with annotations already covering safety, this is close to complete, missing only failure/absence behavior.

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?

With a single required parameter and 100% schema description coverage, the schema already explains that intent_id is the 'remembered.intent_id from route_intent with remember: true'. The description restates the same provenance but adds no new syntax, format, or edge-case meaning for the parameter, so the baseline of 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?

The description identifies the resource ('A payment intent SwapEazi is watching (from route_intent with remember: true)') and enumerates the contents of the response (today's route, cost of paying now, lock-at level, due date, changes), which lets an agent recognize it as a status/snapshot read. However, it never states a verb – no 'returns' or 'shows' – and the clause 'what paying now, locking the rate and holding unhedged need' is grammatically broken, so the purpose must be inferred from the title rather than read directly.

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 pinned by the prerequisite '(from route_intent with remember: true)', which tells the agent this only applies to intents previously persisted via route_intent with remember set. It does not name alternatives for non-remembered intents (e.g. payment_intent or route_intent), so the routing guidance is implicit rather than explicit.

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