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 safety profile is covered. The description adds that data is for the user's watchlist and signals are included 'where available', which is useful context. However, it doesn't disclose what 'market data' includes, whether it's real-time or delayed, or what the output structure looks like.

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, concise and front-loaded with the resource. It earns its place by adding the watchlist scope and the 'where available' qualifier on signals. However, it could be slightly more informative without becoming verbose.

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 read tool with an output schema and safety annotations, the description is mostly adequate. The main gap is that it doesn't clarify the relationship to sibling tools like get_signals_recent or get_brief, which could cause an agent to pick the wrong tool. The output schema likely covers return values, so that's not a gap.

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 has 0 parameters, so there are no parameter semantics to document. The description correctly implies the tool uses implicit context (the user's watchlist). With no parameters, the description doesn't need to explain parameter meaning, and the baseline of 4 applies.

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 states a specific resource ('market data') and scope ('user's watchlist'), and mentions signals. However, it doesn't clearly distinguish this from sibling tools like get_signals_recent, get_brief, or get_today_brief, which could also relate to market data or signals. The verb 'get' is generic but acceptable for a read tool.

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?

No guidance on when to use this tool versus alternatives. With 35 sibling tools including get_signals_recent, get_brief, and get_today_brief, an agent would need to infer usage context. The description doesn't state when to prefer this over get_signals_recent or get_brief.

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