Analyze run history

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description adds meaningful context beyond that: the data source is a local JSONL file written by every run, and it discloses what the flaky view surfaces (pass/fail flips, broken or regressed tests). It omits defaults/limits and any note on history retention or staleness.

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?

One dense sentence with a parenthetical, front-loading the action and data source before enumerating view behaviors. Every clause carries information; the view enumeration is the longest but earns its place. Slightly heavy in a single sentence, but no filler.

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?

With no output schema, the description must carry more weight, and it does explain the return semantics of each view. However, projectRoot (presumably how the history file is located) and limit/lastRuns bounds are left entirely to the schema, leaving the picture partially incomplete for a 5-parameter 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?

Schema description coverage is 60%, so baseline is 3. The description meaningfully expands the 'view' enum by explaining the semantics of each value, adding value over the schema's bare listing. But it says nothing about limit, projectRoot, or lastRuns, so the gap in coverage is not compensated.

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 (local run history), and names the exact backing file .playwright-e2e-mcp/history.jsonl. It enumerates the three view modes with their behaviors, so the agent knows what output families are available. It does not explicitly differentiate from siblings like diagnose-flaky or get-failure, which keeps it from a 5.

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 tells the agent what each 'flaky', 'patterns' and 'test' view does, which implies which view to pick for a given need. However, it never states when to use this tool instead of diagnose-flaky, get-failure, or get-run-status, nor any prerequisites. Usage is implied rather than explicit.

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