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

No annotations are provided, so the description must carry the full burden. It only states 'Add a precious metals purchase' which is the core action, but does not disclose side effects (e.g., appends to portfolio, whether duplicate purchases are allowed), auth requirements beyond the schema's api_key field, or result/return behavior. For a mutating tool, this is insufficient.

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 a single, front-loaded sentence with no wasted words. It states the verb and object concisely. Perfectly effective for its minimal length.

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?

With 7 parameters, no annotations, and no output schema, the description is too minimal. It does not mention what happens after a successful add (e.g., returns updated portfolio or new holding ID), potential errors (invalid API key, duplicate), or how this fits with other tools. A more complete description is needed for safe use.

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%, meaning all parameters (api_key, metal, quantity, weight_oz, purchase_price, etc.) have descriptions. The tool description adds minimal meaning beyond that, merely framing the context as a purchase. Baseline 3 is appropriate as the schema does the heavy lifting.

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 uses a specific verb ('Add') and resource ('precious metals purchase to your portfolio'), clearly distinguishing it from sibling tools like 'get_portfolio' or 'scan_receipt'. The action and target are unambiguous.

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 use when manually adding a precious metals purchase, but provides no explicit guidance on when to use this vs. alternatives like 'scan_receipt' (which may also add holdings) or exclusions. It is clear enough for basic use but lacks explicit when/when-not guidance.

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