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

Annotations already establish readOnly/idempotent/non-destructive, and the description adds substantive behavior beyond them: the review is heuristic and non-exhaustive, issues are only reported when 'provable from the snippet,' and a clean result means 'no provable static issue found' rather than clean code. This calibrates the agent's trust in the output, which is exactly the kind of context annotations cannot convey.

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?

Purpose and the 'use FIRST' directive are front-loaded, and the bolded headers make scanning easy. The workflow block is somewhat repetitive with the opening paragraph's guidance, but every sentence is on-topic and earns its place.

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 an output schema present, the description needn't explain return values, and it correctly focuses on when to call, what the tool can and cannot prove, and how to chain into sibling tools. Complete enough for correct invocation; the only minor gap is that it never mentions the focus/minPriority defaults explicitly in prose.

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 already documents code, focus, and minPriority. The description only implicitly reinforces defaults ('detects the code type', auto-detect) without adding syntax or format detail. Baseline 3 applies when the schema carries the parameter burden.

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 (review) and resource (HTML/CSS/JS frontend code) and immediately characterizes the method: 'conservative, non-exhaustive static heuristic review ... against multiple frontend best practice rules simultaneously.' This clearly separates it from siblings like fix_rule, get_rule, and search_rules, which are retrieval rather than analysis tools.

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?

Explicitly says 'Use this tool FIRST' for any frontend code review and lays out a workflow: follow up each issue with fix_rule or get_rule, and if nothing is returned treat that as inconclusive and continue with search_rules/get_rule. When-to-use and what-to-do-next are both stated.

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