Check quality drift

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

With no annotations, the description must carry behavioral disclosure. It clearly states 'Read-only' and describes the output (per-series delta and slope), which covers the key behavioral traits. It does not document file-missing or empty-history behavior, but for a read-only analysis tool this is acceptable.

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 four short sentences, each earning its place: the resource and purpose, the rationale, the output, and the read-only nature. No filler or redundancy.

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 tool with no output schema, it covers purpose, output, and safety. It lacks explicit handling of edge cases (e.g., missing file, no drift), but the available schema and description provide sufficient context for an agent to invoke it correctly.

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?

Input schema has 100% coverage with descriptive comments for all three parameters, so baseline is 3. The description does not add any parameter-specific details beyond noting the history file path and the concept of slow decline, which is already captured by the schema.

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?

States a specific verb ('Analyze') and resource ('.evalgate/history.jsonl') with a clear purpose: detecting slow decline that per-PR gates miss. This differentiates it from siblings like run_suite or judge_status, which focus on individual results.

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?

Implies usage for detecting cumulative performance drift over time rather than per-PR checks, noting that individual gates can miss gradual declines. Does not explicitly name alternatives or exclusions, but the contrast with 'per-PR regression gate' provides clear context.

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