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

With no annotations, the description carries the burden of disclosing behavior. It does disclose the key return metrics and the 'per metal' grouping, which is useful. However, it does not mention any authentication requirement (api_key is in the schema), data freshness, or whether this is a read-only operation, though 'get' implies safety. It adds some behavioral context but avoids any discussion of potential side effects or edge cases.

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 extremely concise—a single comma-separated list. It is front-loaded with the key output metrics and includes no unnecessary words. It is not a full sentence, but its brevity makes it easy to scan. A slight improvement would be adding a verb like 'Retrieves', but as is, it is appropriately sized.

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 tool with one parameter and no output schema, the description provides a reasonable list of what the agent can expect. It clarifies the grouping by metal but does not explain the response structure, calculation methodology, or how it relates to other analytics tools. The absence of usage guidelines and output schema details leaves gaps in context, but it is still adequate for a simple getter.

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 input schema has one parameter (api_key) with 100% description coverage. The tool description adds no additional semantic meaning about the parameter, so the baseline score of 3 applies. The schema already fully documents what the api_key is and that it is required.

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 title 'Get Portfolio Analytics' and the description listing specific metrics (cost basis, average cost per oz, break-even price, unrealized P/L per metal) clearly indicate the tool retrieves portfolio analytics. It distinguishes itself from sibling tools like get_portfolio by focusing on these specific computed metrics rather than raw holdings. However, the description is a fragment without an explicit verb, relying on the title for the action.

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 provides no guidance on when to use this tool versus the many sibling tools (e.g., get_portfolio, get_daily_brief, get_stack_signal). It does not mention any exclusions or alternative use cases. An agent would have to infer its purpose from the listed metrics, but there is no explicit when-to-use or when-not-to-use information.

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