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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral context: the call costs $0.025 USDC via x402, meaning an agent must consider payment before invoking — exactly the kind of auth/cost disclosure annotations cannot express. It also discloses the 40,000-character input limit and the shape of the output. Lacks any note on latency or failure modes.

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?

A single dense but well-ordered sentence: what it does, input limits, what it returns, then cost. Every clause earns its place and nothing is repeated from the schema or annotations. Front-loaded with the capability, with the payment caveat at the end.

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 readOnlyHint covering safety and no output schema, the description does the necessary work by enumerating the return contents (line numbers, severity, concrete fixes, 0-100 score, positives) and the cost. The gap is input completeness: with four undocumented parameters, no required flags, and no explanation of focus/language, the agent cannot fully reason about a correct call.

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 0% for all four parameters, so the description carries the full burden. It only obliquely gestures at `code` and `url` ('up to 40,000 characters, or a GitHub file URL') and never even hints at `focus` or `language`. With zero required parameters it is also unclear which of url/code the agent must supply, leaving half the surface undocumented in both places.

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+resource and a precise scope: a senior-engineer review of exactly one file, capped at 40,000 characters, accepting a GitHub URL. This cleanly separates it from sibling tools like code_run (execution), report_repo (repo-level analysis) and errorfix (fixing), without the agent needing to open any schema.

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 input constraints (one file, 40k character limit, GitHub file URL accepted) imply when the tool fits, but no alternatives are named and there is no explicit when-not guidance. An agent must infer on its own whether to use this versus code_run, second_opinion or vulns for a security-focused pass.

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