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

No annotations exist, so the description carries the full behavioral burden, yet it discloses no rate limits, auth needs, data-range limits, or error behavior. The '[Personal research only]' tag hints at an access restriction but is not explained, and nothing says how the max_data_points cap affects which weeks come back.

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?

One front-loaded sentence with the resource and return shape in the first clause; nothing is redundant. The bracketed research-use tag is slightly noisy but is short and placed up front.

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 fetch tool with no output schema, the description does name the returned fields (OHLCV, weekly aggregation), which partially substitutes for a return spec. It omits how bars are aligned to calendar weeks, default history span, behavior when max_data_points truncates results, and any access restrictions implied by the research-only prefix.

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 100%, so all five parameters (including date bounds and max_data_points) are already documented in the schema. The description adds only the OHLCV return shape and no extra meaning about symbol format, date semantics, or truncation behavior.

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?

States a specific verb (fetch) and resource (weekly stock time series) and describes the returned content as OHLCV bars aggregated by week. The word 'weekly' implicitly separates it from fetch_time_series_daily and fetch_time_series_monthly, though no sibling is named explicitly.

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?

Usage is only implied by the weekly granularity; there is no statement of when to prefer this over daily/monthly series or over fetch_quote/analyze_stock. The '[Personal research only]' prefix is a licensing caveat, not guidance on selection between tools.

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