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

Discloses several non-obvious behaviors beyond annotations: every chart is inlined with no server cap, metadata always lists the whole group even when a subset is requested, and the image_mode max_images behavior. It also gives an important domain note about the RATES group. This goes well beyond the readOnlyHint and openWorldHint annotations.

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 long but information-dense. Every clause carries practical value, though some ideas repeat (e.g., 'EVERY chart in the group is inlined by default' and 'there is no server image cap'). Front-loading the core function helps, but the length is justified by the tool's complexity.

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 tool with five parameters and non-trivial domain semantics, this description is remarkably complete. It specifies return format (JPEG inline + JSON metadata), aliases, grouping caveats, default behavior, and parameter usage. The presence of an output schema further reduces the need to document return fields, yet the description still covers the essential output content.

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?

Although the schema already documents all parameters at 100% coverage, the description adds substantial meaning: explains the group aliases, the effect of ids (subset with metadata still full), the difference between image_mode values, and the optional max_images hint. This is a model of compensating for schema gaps and enriching parameter understanding.

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 and resource ('Get FRESH charts for every chart in a group'), distinguishes from single-chart tools by emphasizing 'the REAL non-contiguous ids' and describes exactly what is returned (JPEG inline plus JSON metadata). This clearly differentiates it from sibling tools like maatsii_get_chart.

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?

Provides rich context on how to use the tool: accepts friendly aliases, explains the YIELDS vs CREDIT grouping, and details parameter choices (ids, max_images, image_mode). While it doesn't explicitly name alternative tools or state when not to use it, the usage context is clear enough for an agent to decide correctly.

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