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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds the key behavioral detail that the count is specifically about community watchlists, not all watchlists, and frames it as a simple read. No contradictions or hidden side effects; the description complements the annotation with domain-specific context.

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 sentence that is front-loaded with the core question and provides immediate clarity. Every word earns its place without fluff or redundancy. It is appropriately sized for the tool's simplicity.

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?

The tool is simple (one parameter, no output schema, rich annotations). The description clearly states what the tool does, and the return value (a count) is strongly implied by 'How many'. While it does not explicitly describe the response format, the ambiguity is minimal given the tool's purpose. This is complete enough for the complexity level.

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?

Input schema coverage is 100% for the single 'ticker' parameter, described as 'Ticker symbol'. The description does not add extra format, constraints, or examples beyond the schema. Per the baseline for high schema coverage, the description adds no additional semantic value, so a 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 explicitly states the tool's function: counting how many community watchlists include a given ticker. This is a specific verb+resource combination that clearly distinguishes it from sibling tools like 'check_ticker_in_my_watchlists' (personal watchlists) and 'discover_community_watchlists' (listing watchlists). The phrase 'a simple read' reinforces its purpose as a quick popularity metric.

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: 'a simple read on what the club is tracking' implies when to use this tool for a quick gauge of community interest. It does not explicitly name alternatives, but the contrast with sibling tools is evident from the tool name and description. No exclusion criteria are given, but the contextual guidance is sufficient.

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