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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds genuine value by disclosing the returned field set (including 'masked card', signaling PII is redacted) in the absence of an output schema. It stops short of describing error behavior for unknown ids or any pagination/rate considerations.

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 compact sentences, front-loaded with the verb+resource and then the returned fields, ending with the underlying endpoint. No filler.

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 single-parameter read tool with no output schema, listing the response fields fills the main gap an agent would have. Minor omissions remain (not-found behavior, whether any fields can be null), but nothing needed to invoke it correctly is 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%, with transaction_id documented including its provenance ('from givingfuel_list_transactions'). The description adds nothing about the id beyond 'by id', so the schema carries the full load and 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?

Names a specific verb and resource ('one transaction by id') and enumerates the payload it returns (amounts, type, payment method, masked card, gateway message, status), which makes the fetch-single semantics unmistakable. It doesn't explicitly contrast itself with givingfuel_list_transactions, so sibling differentiation is only implied by 'by id'.

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 implied rather than stated: 'one transaction by id' signals a single-record lookup, and the schema description points to givingfuel_list_transactions as the id source. No explicit when-to-use/when-not guidance appears in the description itself.

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