module_variable

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

With no annotations the description carries the full burden, and it discloses several non-obvious behaviors: every candidate is returned on name collisions rather than one being chosen, a fallback to name/meaning search occurs on no exact match, and results are exhaustive rather than truncated. No authentication or side-effect context is given, but for a read-only code-analysis lookup this is strong disclosure.

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?

Front-loaded with the core definition of what is returned, followed by behavioral rules. Dense and mostly earning its place, though a couple of sentences are run-on and the parenthetical example is a touch verbose.

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?

No output schema exists, so the description must describe the return shape; it enumerates the fields (module, type, full declaration, line, units, meaning) and notes exhaustiveness. That is sufficient for correct invocation, with only minor gaps around result structure/ordering.

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 both parameters are already documented (name with an example, module as disambiguator). The description reinforces purpose but adds no syntax or format detail beyond the schema; the multi-module sentence implies the role of the module parameter but doesn't define it. Baseline 3 is appropriate.

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?

States a specific resource (a module-declared variable) and precisely what is returned: declaring module, type, full declaration, line, units and meaning. It explicitly distinguishes itself from a sibling, noting this covers program global state which 'describe_type cannot confirm exists'. An agent can route to it without opening another schema.

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?

Clear context: use it to find a variable declared in a module body, with an explicit contrast against describe_type as the tool that cannot confirm such existence. It also explains the multi-module return rule and the fuzzy fallback, which guides invocation. It stops short of a full when/when-not routing across all siblings, so not a 5.

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