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

Without annotations, the description carries the full burden. It does disclose that outputs are 'full v1 objects' plus a difference row with named metrics, and includes a disclaimer that ratings are opinions, not predictions or financial advice. However, it doesn't explicitly state read-only behavior or mention any side effects, though it's implied by the comparative nature.

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 concise sentences: the first front-loads the main purpose and output, the second adds a necessary caveat. No wasted words, and the key information is presented first.

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 lists the specific metrics included in the difference row and mentions 'full v1 objects', giving a decent sense of the return structure. However, with no output schema and no annotations, it doesn't mention how assets are identified, potential error conditions, or any prerequisites. It's reasonably complete for a simple compare tool but leaves some gaps.

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 for the 'assets' parameter. It only says 'up to five assets' but doesn't specify the expected format (e.g., ticker symbols, IDs) or that they are strings. The description adds little beyond what the schema already shows (array of strings, min 2 max 5), failing to provide any practical guidance on how to construct the parameter.

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 compares up to five assets side by side and provides a difference row with specific metrics. It distinguishes itself from siblings by emphasizing the comparative output and the difference row, though it doesn't explicitly name alternative tools. The verb 'compare' is implicit in the name and description, and the resource (assets) is clear.

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?

There is no explicit guidance on when to use this tool versus its siblings (e.g., coingraph_evaluate, get_movers). The description implies it's for multi-asset comparison but doesn't state conditions or exclusions. An agent is left to infer use cases from the tool name and description alone.

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