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

Annotations already provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe, reproducible read operation. The description adds the pagination cursor context (via the cursor param) and the date-range-or-latest-count scoping. It doesn't disclose rate limiting or any other behavioral caveats, but with strong annotations the burden is lower; a 3 is appropriate.

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 single-sentence description is tight and front-loaded with the core purpose. It covers both invocation modes (date range, latest count) efficiently with zero filler. Slightly more structural clarity around cursor/pagination could help, but for a purpose statement it's well-sized.

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 presence of an output schema means the description needn't document return structure. With 6 params (only 1 required), a two-mode invocation, an output schema, and strong read-only annotations, the description covers the essential input semantics and invocation modes. It's reasonably complete for a medium-complexity historical-data retrieval tool; minor gaps around pagination behavior remain but are acceptable.

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 description coverage is 50% and each parameter already has inline descriptions (symbol, limit, order, cursor, start_day, end_day, plus patterns and defaults). The description adds the meaning that the tool is the source of the 'latest trading-session count' semantics tied to limit, which adds some value. With 50% coverage and moderately documented params, the description partially compensates but doesn't fully carry param meaning, so baseline 3 fits.

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 verb (return) plus resource (daily prices and volume) and scoping (one ticker by date range or latest trading-session count). It's specific about the primary use case. However, it doesn't explicitly distinguish from sibling market_quote (real-time single quote) or market_fundamentals, though 'daily prices and volume' vs 'quote' is implicitly differentiated.

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 conveys the tool fetches historical price data by either date range (start_day/end_day) or a count of trailing trading sessions (limit), which is reasonable usage context. But it doesn't explicitly state when NOT to use it or point to alternatives like market_quote for real-time prices, so the when-versus-alternatives guidance is implied rather than explicit.

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