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

With no annotations, the description must carry transparency. It discloses that the tool 'Costs DAC', a behavioral side-effect, and states the report is 'structured for external audit review'. It does not explicitly mention read-only nature or side effects beyond cost, but for a GET-style tool this is acceptable. It adds context beyond the schema by highlighting cost and audit purpose.

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 core purpose, then lists report contents, and ends with the cost note. No wasted words, easy to scan, and every sentence adds value.

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-generation tool with no output schema, the description adequately conveys what the report contains (metadata, EE resolution, responsibility declaration) and the cost implication. It lacks details on output format (e.g., JSON, PDF) but that is not essential given the tool's nature. Overall, it is sufficiently complete for an agent to understand what it returns.

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%, so the schema fully documents all parameters. The description does not add any additional parameter meaning beyond what the schema already provides. The payment flow is explained in the schema itself, not the description. Baseline 3 is appropriate given high schema coverage.

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 this tool generates an 'external-audience evidence report' for a decision, which is a specific verb+resource. It distinguishes from sibling tools like get_decision by focusing on external audit context, and mentions specific contents (metadata, EE resolution, responsibility declaration).

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 implies it is for external audit reporting of decisions, and notes it 'Costs DAC'. However, it does not explicitly state when to use this over other get_* tools, nor provide exclusions or alternatives. Some guidance is implied via the external-audit wording, but not explicit.

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