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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the behavioral context that this is a batch call returning the latest value for many metrics, and that metrics is comma-separated. It doesn't disclose pagination, response format, or rate limits, but for a read-only batch tool with strong annotations, a 3 is appropriate.

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 with no waste. The core purpose is front-loaded, and the comma-separated detail and mirror reference are placed efficiently. 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 simple 2-parameter read-only tool with strong annotations, the description is mostly complete. It tells the agent the key usage pattern (many metrics, one asset, single call) and the comma-separated format. However, it doesn't specify the asset identifier format or the response shape, and with no output schema, an agent might not know what to expect back. The mirror reference helps but doesn't fully resolve this.

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 0%, so the description must compensate. It does clarify that 'metrics' is comma-separated, which adds meaning beyond the schema's bare string type. However, it doesn't explain the format of 'asset' (e.g., ticker, ID, slug) or provide examples. The description adds some value but doesn't fully compensate for the 0% schema coverage.

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 ('get'), resource ('metrics'), and scope ('MANY metrics for ONE asset in a single call'). It clearly distinguishes itself from the sibling get_metric_timeseries_multi by calling itself the 'mirror' of that tool. However, it doesn't explicitly name the sibling in the description, relying on the sibling list for context, so it's not a full 5.

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 when to use this tool: when you need the latest value of many metrics for one asset in a single call. It also references the sibling get_metric_timeseries_multi as its mirror, which hints at the alternative for timeseries data. However, it doesn't explicitly state when NOT to use it or provide a direct comparison with other metric tools like get_metric_timeseries or get_metric_metadata.

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