blacksmith_cost_by_repo

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

No annotations are provided, so the description carries the full burden. It only states the grouping and timeframe, but does not disclose whether this is a read-only operation, any default behaviors (e.g., default org, default month), or output characteristics. The description adds minimal behavioral context beyond what the tool name implies.

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, concise sentence with no filler words. It is appropriately front-loaded, starting with the key concept. However, the brevity contributes to under-specification, so it doesn't earn a 5.

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?

Given the tool's simplicity (2 optional params, no output schema, no annotations), the description conveys the essential grouping and timeframe. However, it does not specify whether the output is a list, a total, or how it relates to the org parameter. With many sibling cost tools, more context about the return format or typical use case would improve completeness.

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%, with both 'org' and 'month' parameters having clear descriptions that include defaults and meaning. The description does not add any extra parameter semantics, so the baseline of 3 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 clearly states the resource (cost) and the grouping dimension (by repository) with a time scope (for a month). While it lacks an explicit verb like 'get' or 'list', 'broken down' conveys an aggregation/listing action. It is distinguishable from sibling tools like cost_daily or cost_by_runner due to the explicit 'by repository' grouping.

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 provides no guidance on when to use this tool over alternatives. It does not mention any context, exclusions, or sibling tools for comparison. Users must infer from the name which scenario it fits.

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