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

The description states 'Read-shaped tools only (anything that buys, sells or writes refuses)' which directly contradicts the annotation readOnlyHint=false. This is a serious inconsistency. It also adds some behavioral context about data fidelity ('their data comes back as it is'), but the contradiction undermines transparency. Per the rubric, any contradiction scores 1.

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 core purpose is front-loaded in the first sentence, but the description includes significant extraneous content: 'Singularity Agent's MCP server, a live seat on The Wall (hosted by them). Called through their seat; their data comes back as it is.' and a listing URL. These do not help an agent call the tool correctly and detract from conciseness. The description is longer than necessary.

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?

The description explains the main functionality and the chain-search behavior, but it lacks details about the return format (no output schema) and the normalization specifics. More importantly, it contradicts the readOnlyHint annotation, which creates confusion about whether the tool performs writes. This is a critical gap for an agent deciding to invoke it.

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?

There are 0 defined parameters and the schema is an empty object with additionalProperties: true. The baseline is 4 for zero parameters. The description adds a hint about a 'chain' parameter ('If no chain is given'), which implies an optional parameter exists beyond the schema. This adds some semantic meaning, though it doesn't fully describe parameter formats or allowed values.

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 clearly states the action: 'Fetch and normalize a transaction' with EVM calldata decoding. It identifies the resource (transaction) and a specific behavior (normalization, decoding). It doesn't explicitly name sibling tools but the purpose is distinct enough from siblings like balance or history. The verb+resource is specific.

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 a conditional about chain ('If no chain is given, searches the chains the hash format allows') but provides no explicit guidance on when to use this tool versus alternatives. No sibling tools are mentioned, and there's no 'use this when...' or 'prefer X instead' statement. Usage context is only implied by the read-only constraint.

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