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

No annotations are provided, so the description carries the burden. It discloses the output shape (one-line risk shape with four specific attributes) and that filters combine with AND. However, it doesn't disclose pagination behavior, rate limits, or what happens when no contracts match. The description adds meaningful behavioral context but leaves some operational details uncovered.

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?

Three sentences with no waste. The core purpose and output shape are front-loaded, the usage guidance is in the second sentence, and the filter semantics are in the third. Every sentence earns its place.

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 list tool with no output schema, the description adequately explains what the return contains (one-line risk shape with four attributes). It doesn't mention pagination or result limits beyond the schema's 'limit' parameter, but the tool is simple enough that the description is nearly complete. The missing operational details (pagination, empty results) are minor for this tool's complexity.

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%, so the schema already documents all four parameters. The description adds the AND-combination semantics for filters, which is useful beyond the schema. However, it doesn't add detail about the 'limit' default behavior or the exact meaning of 'upgradeable' beyond what the schema says. Baseline 3 is correct because the schema does the heavy lifting and the description adds only marginal filter semantics.

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 states a specific verb ('List'), a specific resource ('EVM contracts in the Contract Powers registry'), and the exact risk-shape fields returned. It clearly distinguishes itself from siblings by focusing on the registry listing with risk summaries, not a single contract lookup or power changes.

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 explicitly says 'Use this to see what is already analysed before spending a lookup,' which gives clear context for when to use it. It doesn't explicitly name alternatives or exclusions, but the sibling names and the listing-vs-lookup distinction imply when not to use it. A 4 is appropriate because the usage context is clear but no explicit alternative routing is given.

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