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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds useful behavioral context by listing return fields and explaining status code semantics (0x1=success, 0x0=fail), which helps the agent interpret results beyond what annotations provide.

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 sentences, front-loaded with the primary purpose, followed by a compact list of return fields. No fluff or repetition, making it highly efficient.

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-only lookup, the description covers the essential return fields (status, gasUsed, contractAddress, logs) despite lacking an output schema. It is adequate for common use, though it does not detail nested log structures or error 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?

The input schema has 100% coverage with a clear description for the hash parameter (type, pattern, and meaning). The tool description adds no additional parameter semantics beyond referencing 'by hash', so it does not exceed the baseline of 3.

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?

Description clearly states 'Get transaction receipt by hash on Mezo' – a specific verb (get), resource (transaction receipt), and scope (by hash on Mezo). It distinguishes from siblings like mezo_get_transaction (transaction vs receipt) and eth_get_transaction_receipt (different chain).

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 gives clear context that this is for Mezo chain and receipt lookup only, which implicitly differentiates it from alternatives like mezo_get_transaction or eth_get_transaction_receipt. However, it does not explicitly name alternatives or exclusions, so it stops short of a 5.

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