core-install

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

Annotations already declare non-readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds genuinely useful context beyond that: installation is slow on first run, and certain cores (esp32) need a board-manager URL. It does not cover permissions or output, but for this tool the timing caveat is the key operational fact.

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 compact sentences with the core purpose first and the operational caveat second; no filler, every clause carries information.

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 three-parameter, no-output-schema install tool with annotations covering safety, the description plus schema gives an agent enough to call it correctly, including the slow first-install expectation. It could say a bit more about prerequisites (e.g., needing the board index URL configured) but is otherwise complete.

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 coverage is 100%, so coreId, version, and additionalUrls are all documented in the schema, including the 'omit for latest' convention. The description's example IDs and the esp32-needs-URL note reinforce rather than extend that, so it sits at the baseline.

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 ('Install a board core') and illustrates the resource with concrete IDs ('arduino:avr', 'esp32:esp32'). This clearly separates it from siblings like core-upgrade, core-search, and lib-install without needing to name them.

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?

Usage context is implied by naming the operation and giving examples, and it usefully notes that esp32 requires an additional URL. However, it never states when to prefer this over core-upgrade, nor any preconditions for installing a core.

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