get_instruments

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

No annotations are present, so the description carries the full burden. It does disclose the return format (JSON array with internal names and display labels), which is a behavioral detail. However, it omits any statement about it being read-only, permission requirements, or edge-case behavior (e.g., empty project), leaving some ambiguity.

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 two concise, well-structured sentences: the first states the purpose, the second specifies the return format. Every word earns its place, and the 'Returns:' label provides clear structure.

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 zero-parameter read-only listing tool, the description covers the essential function and output format. The presence of an output schema further reduces the need to explain return values. A brief mention of using get_metadata for field-level details would enhance completeness, but it's not a critical gap.

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 tool has zero parameters, so the description is not responsible for explaining any. The baseline for no-parameter tools is 4, and the description correctly avoids adding unnecessary parameter details.

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 function with a specific verb ('Get the list of instruments') and resource ('in the REDCap project'), including a parenthetical clarification that instruments are forms/surveys. It does not explicitly differentiate from sibling tools like get_metadata, which also provides project structure, so it misses the highest mark.

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?

No guidance is provided on when to use this tool versus alternatives such as get_metadata or get_project_structure. The description merely states what it does without any contextual pointers, exclusions, or preferred use cases.

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