Finviz-only: rendered chart PNG

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

With no annotations supplied, the description carries the full behavioral burden. It does usefully disclose that the result is a file saved to disk with a path and dimensions and that the envelope is labelled FINVIZ, plus the provider limitation. It does not cover auth/API-key requirements, failure behavior, or cost/rate limits, which matters for a provider-restricted rendering call.

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?

Front-loaded with the core purpose, then organized into compact Args/Returns blocks with zero filler. The TradingView explanation is relevant context rather than padding. Slight redundancy between the opening line and the Returns line, but overall efficient.

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 straightforward render-and-save tool whose return shape is already covered by an output schema, the definition supplies what an agent needs to call it correctly, including the param code legends. Remaining gaps (provider/auth prerequisites, error cases) are modest given the tool's simplicity.

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 0% and none of the string params carry enums, so the description does the heavy lifting: it maps period to d/w/m, chart_type to c/l/h, and scale to l/log, which is essential information the schema omits entirely. It documents all six parameters, though it gives no guidance on sensible width/height ranges.

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+resource: 'Rendered PNG candlestick chart for a ticker', which is unambiguous. It also implicitly distinguishes itself from text-based charting siblings by explaining that TradingView's provider computes charts as text analysis rather than images, making this PNG path Finviz-only. A slightly more explicit naming of the sibling (e.g. technical_analysis) would push this to a 5.

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 context is implied rather than stated: the agent can infer 'use this when you need an actual image, not a text-based chart', and the 'Finviz-only' framing hints at a provider prerequisite. However, there is no explicit when-to-use/when-not phrasing, no named alternative, and no statement of what happens if the Finviz provider is unavailable.

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