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

The readOnlyHint annotation already establishes the tool's read-only nature, and the description adds meaningful behavioral details: the library is global and static, and passing guidanceId returns a single entry instead of the full list. This complements the annotation without any contradiction.

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 well-structured with three sentences, covering purpose, parameter behavior, and usage guidance. It is slightly verbose in repetition (e.g., mentioning 'guidanceId' twice and the global scope), but overall it is clear and efficient.

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?

All essential context is present: what the tool returns, the effect of the optional parameter, the library's global/static nature, and the recommended alternative for finding-specific advice. Given the tool's simplicity and lack of output schema, no further information is needed for correct use.

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?

The schema provides a description for guidanceId with an example ('api2-jwt-alg-none') and notes it returns the entry with code examples, giving 100% coverage. The tool description further clarifies the parameter's effect (single entry vs. list), adding value beyond the schema baseline.

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?

The description clearly states that the tool lists the static security guidance library with one entry per OWASP API-security issue, and it explicitly contrasts this with get_finding_remediation. The verb 'List' and the resource 'security guidance' are specific, and the purpose 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?

The description provides explicit guidance on when to use this tool: 'Use this for the general library; for advice on one finding use get_finding_remediation.' It also explains how to retrieve a single entry by passing guidanceId, covering both main usage scenarios and the alternative.

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