transaction_lookup

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

With no annotations to carry the burden, the description fully discloses behavioral traits: it is read-only, makes one GET request, does not auto-fetch continuation pages, returns an error for unknown IDs, imposes local array limits, reports truncation, and refuses oversized records. This is unusually thorough and gives the agent a complete safety and behavior profile.

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?

The description is dense but well-structured: it opens with purpose, then covers behavior, filter semantics, and limits. Every sentence contributes a distinct detail, and nothing feels redundant. It could be slightly tightened, but the front-loaded purpose and logical flow keep it effective.

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?

Given the absence of annotations and output schema, the description is remarkably complete. It covers error behavior, side effects, pagination, size limits, and parameter caveats. The only gap is a more explicit description of the return payload structure, though the mention of 'JSON-encoded string wire types' offers some guidance.

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 0%, so the description must compensate. It assigns meaning to trx_id as the explicit lookup key and clarifies that the optional parameters (username, card_detail_id) are 'forwarded as supplied' without guaranteed effectiveness. This adds practical semantic guidance beyond the bare schema, even if it doesn't fully define each parameter's domain.

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 opening sentence, 'Read one game transaction by explicit trx_id,' combines a specific verb, resource, and identifier, making the tool's purpose unmistakable. Additional statements like 'This never submits or retries a game transaction' further differentiate it from write-oriented tools without naming siblings.

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 description clearly implies when to use the tool (when a transaction ID is available and a single read is needed) and even states a when-not ('never submits or retries'). However, it does not explicitly reference any sibling alternatives (e.g., cards_trx_lookup, transaction_inspect) or provide routing criteria, leaving usage guidance 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.