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

With empty annotations, the description carries the burden of behavioral disclosure. The verb 'List' clearly indicates a read-only operation, and the description adds context by stating that each entry returns a blockchain_fk 'for later use', hinting at the purpose. It does not disclose rate limits or error handling, but for a simple list, the behavior is largely transparent. No contradiction with annotations.

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 short but redundant, effectively stating the same thing twice in the first two sentences. It front-loads the purpose, which is good, but the duplication wastes space. The param/return sections are useful and structurally clear. Overall, it is not maximally concise due to the repetition.

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 simple list tool with one parameter and an output schema, the description is fairly complete. It explains the parameter, the nature of the return (blockchain_fk values), and notes the output is JSON. Since an output schema exists, detailed return format is not needed. It does not cover edge cases, but none are strongly expected for a list of supported blockchains.

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 schema only defines api_key as a required string with no description, and schema coverage is 0%. The description compensates by explaining that api_key is 'the api key allocated to your application', adding meaningful context. This is sufficient for the single parameter and goes beyond the schema's bare definition.

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 tool lists all supported blockchains and returns blockchain_fk values for later use. It uses a specific verb ('List') and resource ('supported blockchains'), and the repetition reinforces the purpose without ambiguity. It differentiates from sibling tools by focusing specifically on blockchain identifiers rather than digital assets or crypto info.

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 implies usage (to obtain blockchain_fk values for later use) but provides no explicit guidance on when to choose this over alternatives. It does not mention any exclusions or alternative tools. For a simple list tool, the implied context is adequate but not explicit.

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