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

With no annotations, the description carries the full behavioral burden and does so well: it discloses the critical false-negative risk ('regex pattern matching, not a real parser -- treat a clean result as didn't find a problem'), explains why one pattern matters (dunning marks past_due/unpaid, not canceled), and states the data-handling guarantee ('Nothing pasted is stored').

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 purpose and input instruction are front-loaded, and each later sentence adds non-redundant value (limitation caveat, privacy note). The first sentence is dense with a long parenthetical explaining the dunning scenario, which is useful but makes it less scannable than it could be.

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?

There is no output schema and no annotations, yet the description covers input expectations, the nature of the output (findings for named bug categories), the accuracy limitation, and data retention. An agent has everything needed to call this correctly and interpret results cautiously.

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?

Only one parameter exists and the schema already documents it at 100% coverage, so the baseline is 3. The description goes further by clarifying the expected content and that two files can be concatenated, which the schema's short field description does not convey.

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 precise verb+resource ('Paste Stripe integration source code ... get back pattern-based findings') and enumerates the exact bug classes it detects (missing signature verification, missing customer.subscription.updated handling, missing checkout metadata, premature customer creation). No sibling tool exists, so no differentiation is needed, and the scope is unambiguous.

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?

Specifies exactly what input to supply (a webhook handler, a checkout-session-creation route, or both concatenated), which is the key usage condition for a single-input analysis tool. There are no alternatives to route between and no explicit when-not-to-use clause, so it falls just short of a 5.

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