get_control

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

With no annotations, the description carries the behavioral burden, and it excels: it discloses that null is returned for both nonexistent and out-of-scope controls, and explicitly explains the deliberate indistinguishability for security. This is exactly the kind of non-obvious behavior an agent needs to know.

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 entire description is one tightly packed sentence with no filler. It front-loads the core purpose and then adds the crucial null-behavior caveat, earning every word.

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?

For a single-parameter read tool with an output schema, the description covers the key contextual points: what it returns, when it returns null, and why null is ambiguous. The security rationale is an important contextual addition that prevents an agent from misinterpreting failed lookups.

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%, so the description must compensate. It implies control_id identifies the single control but does not explain the expected format or source of valid IDs. The parameter name and 'one control' wording make it inferable, but the description does not directly elaborate on the parameter.

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 states a specific verb and resource: 'Full detail for one control.' This clearly distinguishes it from list-oriented siblings like list_controls and get_control_coverage by emphasizing singular detail retrieval.

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 gives clear context: use this when you need full detail for a single control, not a collection. It does not explicitly name alternatives or state when not to use it, but the 'one control' framing implies the appropriate selection.

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