distil_savings

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

Annotations already provide readOnlyHint: true, destructiveHint: false, and idempotentHint: true. The description adds that it takes no arguments and that an empty ledger reports zeros, which is transparent. There is no contradiction with 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 two sentences, front-loaded with the result format and purpose. Every sentence adds value without redundancy, achieving high conciseness.

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 no parameters, no output schema, and annotations covering safety, the description completely explains the return format, scope (all requests on machine), and what it does not tell (correctness). It is fully adequate for the tool.

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?

With zero parameters, the baseline is 4. The description correctly states 'Takes no arguments', which is clear and sufficient for the parameter semantics dimension.

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 reports cumulative savings from the distil ledger with specific fields (runs, tokens_saved, dollars_saved). It distinguishes from sibling tools by clarifying it says nothing about compression correctness, which differentiates it from distil_compress and distil_expand.

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 explicitly says to use it to answer 'how much has distil saved me' and notes it covers all requests on the machine, not just the session. It does not explicitly state when not to use it or mention alternative tools, but the context is clear enough.

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