get_cost_report

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

With no annotations, the description fully conveys it is a read-only report tool (returns grouped cost summary). It does not mention permissions or side effects, but the context makes the behavior clear.

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?

Two sentences with no fluff; the first sentence defines purpose and output, the second adds context. Every word earns its place.

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 report tool with two optional parameters and no output schema, the description fully covers what it does, what it returns, and when to use it. No gaps remain.

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 coverage is 100%, but the description adds value by explaining the output fields (total USD, job count, etc.) and the meaning of grouping options, going beyond the schema's parameter descriptions.

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 it is a 'Longitudinal cost breakdown for research budget tracking' and specifies the exact output (total USD, job count, avg cost per job, avg score). It differentiates from the sibling tool 'cost_summary' by emphasizing longitudinal grouping and specific fields.

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 explains it is 'useful for tracking spending by repo, day, or outcome', which implies usage context. However, it does not explicitly contrast with the sibling 'cost_summary' or state when not to use it.

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