diff_runs

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

Describes what the tool surfaces (changes, regressions, etc.), but with no annotations, the description lacks information on side effects, permissions, or whether it reads/writes. The behavior is implied but not fully transparent.

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, front-loaded with purpose, no fluff. 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?

Covers the main use case and output types, but lacks details on output format (though format parameter is in schema) and prerequisites like file existence. Given no output schema, it is fairly complete.

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 covers all parameters with descriptions; the description adds context about the comparison but does not provide additional semantics beyond the schema for each parameter.

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?

Description clearly states it finds changes between two run artifacts, listing specific types (regressions, recoveries, schema drift, gate status changes). However, it does not differentiate from sibling tools that may also compare runs or history.

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 a specific use case 'Essential after updating a server', but does not include when to avoid using it or alternative tools for similar tasks.

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