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

With no annotations, the description carries the full transparency burden. It discloses a key behavioral trait: the presence or absence of api_key changes the nature of the answer (personalized vs. general). It also defines the domain scope ('anything about precious metals, markets, your stack'). This adds meaningful context beyond the bare parameter schema.

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, each earning its place. The first states the purpose, the second explains the optional parameter's usage. No unnecessary detail or repetition. Front-loaded with the verb and resource.

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 chat tool with two parameters and no output schema, the description covers the essentials: what it does, the domain, and how the optional parameter affects behavior. It does not describe the return format, but for a conversational tool this is largely implicit. Overall, sufficiently complete.

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 100%, so baseline is 3. The description adds value by explaining the behavioral consequence of omitting api_key ('or omit for general market analysis'), which the schema alone does not fully convey. The message parameter is self-evident, but the description's clarification of the optional parameter's effect earns a 4.

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's purpose: 'Ask Troy anything about precious metals, markets, your stack.' It uses a specific verb ('Ask') and identifies the resource ('Troy'), while distinguishing it from sibling data-retrieval tools by positioning it as an interactive chat/Q&A interface.

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 clear context on when to use the tool: for asking questions about precious metals, markets, or one's stack. It also gives guidance on the optional api_key parameter ('Provide api_key for personalized portfolio-aware answers, or omit for general market analysis'), though it does not explicitly exclude alternatives or name specific sibling tools.

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