can_read

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

No annotations are provided, so the description carries the behavioral burden. It discloses the response shape and precisely defines the three possible values of via, including None on denial. It doesn't discuss side effects or auth, but 'Explain' strongly implies a read-only decision lookup.

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?

Two sentences with no filler. The output contract is front-loaded, the via values are explained compactly, and the usage guidance is delivered in the final sentence.

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 no output schema and no parameter descriptions, the description covers the main return contract and the core use case, but it stops short of fully documenting parameter meaning and edge-case behavior. It is adequate for basic invocation but leaves some details to inference.

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 has 0% description coverage, so the description must compensate. It implies that id identifies the record and agent identifies the actor whose access is checked, but it never explicitly defines either parameter or their acceptable formats. The via explanation adds useful context but leaves parameter semantics partially implicit.

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 opens with a specific action and object: 'Explain ONE access decision' with the exact output fields. It also contrasts itself with recall-based inference, which helps distinguish it from the many sibling 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?

It explicitly says to use it 'to inspect an ACL a record at a time' and warns against 'inferring it from what a recall did or did not return.' This gives clear when-to-use and when-not-to-use guidance.

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