keil_read_variable

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

With no annotations, the description carries the full burden and does disclose the important behavior: the read is 'fresh' (taken from the live target, not a cached snapshot), requires a halted state, and is limited to global/static base-type symbols. It does not describe what happens on an unknown or out-of-scope name, nor that errors surface via keil_get_last_error.

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 short sentences with zero filler; the positive capability comes first and the exclusion follows immediately. Every clause conveys a constraint the agent needs.

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?

A single-parameter read tool with an output schema and no annotations is a modest ask, and the description covers preconditions and supported symbol classes. The remaining gap is the concrete format of the name argument and failure behavior, which an agent may need before calling.

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 gives only an undescribed 'name' string at 0% coverage, so the description must compensate. It does add meaning by constraining the name to a global/static base-type variable and implying an unambiguous (qualified) form, but it never specifies the expected naming syntax or whether module prefixes are required.

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 verb and resource (read a variable), plus the qualifying scope: global/static base-type only, and only while halted. This clearly separates it from a general expression evaluator. It does not name the plural sibling keil_read_variables, so the agent must infer the batch-vs-single distinction from the name alone.

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?

Gives an explicit precondition (target must be halted) and explicit exclusions (locals and expressions unsupported), which is real when-not guidance. It stops short of naming the alternative to use for locals or batch reads, so routing to keil_read_variables is left implicit.

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