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

With no annotations provided, the description carries the full burden. It discloses the underlying AWS engine (SimulateCustomPolicy), the exact output structure, the behavior when credentials are missing (verified=unknown with reason), and the preprocessing of wildcarded operations. This is substantial behavioral transparency beyond minimal expectations.

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 three sentences long, front-loaded with the core purpose, followed by output format and prerequisites. Every sentence contributes meaningful information without redundancy or fluff.

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?

Given the lack of an output schema, the description adequately explains the return values (verified, grants_all, grants_extra) and the credential prerequisite, including the fallback behavior. It does not precisely define what grants_all and grants_extra signify, but the context is sufficient for an agent to understand the tool's basic usage and interpretation.

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 description is not required to repeat parameter definitions. It adds some context by explaining that 'operations' are intended IAM actions and that wildcards are expanded, but it does not elaborate on the 'workflow' parameter beyond what the schema already states, keeping the added value at 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 the tool's purpose: verifying a generated policy against intended operations using AWS's SimulateCustomPolicy engine. It specifies a concrete action and resource, and distinguishes itself from siblings like 'policy' which generates policies.

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 implies usage after policy generation ('Feed a generated policy back') and identifies a key prerequisite (AWS credentials). However, it does not explicitly mention when to avoid using this tool or name alternative verification approaches, so guidance is clear but not exhaustive.

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