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 agent knows this is a safe read operation. The description adds useful behavioral context: it returns an empty items[] array when nothing is starred, includes a pro-tier gate, and provides a disclaimer. These details go beyond the annotations without contradicting them.

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 well-structured: a one-sentence purpose, a bulleted list of return fields, and a note on empty behavior and pro tier. It is front-loaded with the key point, uses bullet points for readability, and contains no filler. 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 zero-parameter tool, the description is fully comprehensive. It details the output structure (including fields, types, and ranges), explains the empty case, specifies the pro-tier requirement, and provides a disclaimer. The output schema further enriches this, but the description itself is sufficient for an agent to call the tool correctly without external 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?

The tool takes zero parameters, and the schema coverage is 100% (empty properties). Since there are no parameters to explain, the description does not need to add parameter semantics. The baseline for no parameters is 4, and the description correctly focuses on the output and usage.

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 opens with a specific verb and resource: 'The caller's Stocklake watchlist (starred symbols from the web dashboard)'. It immediately distinguishes this from the sibling tools (e.g., get_market_movers, get_stocks) by focusing on the personal watchlist. The enrichment details ('live price, technicals, and AI verdict') further clarify the 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 provides clear context: it is specifically for the caller's own watchlist, and it notes the 'Pro tier only' requirement. It also gives an explicit fallback for the empty case ('star symbols at stocklake.dev/dashboard'). However, it does not name any alternative tools or state when not to use it, leaving the agent to infer that this is the go-to for the watchlist.

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