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

Annotations include readOnlyHint: true, so the description doesn't need to repeat that this is a read-only operation. The description adds valuable context about rate limits and pricing (5/day anonymous, 10/day signed-in, 50/day power, $0.01 per call beyond), which is non-obvious and helps the agent anticipate costs and limits. It does not explain output structure (since no output schema is provided), but for a read-only list query, that's a minor gap given the annotation covers safety.

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, concise sentence that front-loads the core purpose ('Every stock screen a given ticker is currently in') and then includes critical usage constraints (pricing and rate limits) in a compact, readable way. No unnecessary words or repetition; every part adds value.

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 read-only tool with a single parameter and no output schema, the description is quite complete. It covers the tool's scope, rate limits, and pricing. The only missing detail is the exact output format (e.g., whether it returns list names, metadata, etc.), but given the simplicity and the fact that it's a listing operation, this gap is minor. It's not a complex tool requiring extensive context.

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 descriptions cover 100% of parameters: 'symbol' is described as 'Ticker symbol, e.g. NVDA or BRK-B.' The description doesn't add any new meaning to the parameter; it just confirms that the symbol is input to finding lists. Since the schema already covers the parameter adequately, baseline 3 is appropriate.

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: to find all stock screens (momentum, technical-signal, earnings, theme, thesis) that a given ticker is currently in. It names the specific resource (stock screens) and the action (find/list), and distinguishes it from sibling tools like list_smart_lists (which likely lists predefined lists) and get_smart_list (which gets details of a specific list). The phrase 'in one call' adds clarity about the comprehensive scope.

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 all memberships of a ticker across different screen types. It provides clear context (one call vs. multiple calls) and even includes pricing tiers, which can guide usage (e.g., be aware of rate limits). However, it does not explicitly state when NOT to use it or mention alternatives (like get_smart_list for a single list's details).

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