set_stacks_api_url

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

No annotations exist, so the description carries the full burden, and it does disclose the key side effect: this redirects ALL Stacks API requests globally, not just one call. It also gives the compatibility requirement (must serve /v2/ and /extended/v1/). It leaves gaps on persistence (does it survive restart?), whether it takes effect immediately, and validation/rejection behavior for a bad URL.

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 core is well front-loaded: action, when to use, URL requirements, example. However, the closing 'Tip: call earning_opportunities to see how to put your assets to work' is unrelated promotional content that does not help an agent decide whether or how to call this tool.

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 one-parameter config setter with no output schema, the description covers purpose, prerequisites, and URL format well enough to call correctly. Missing pieces are persistence/revert semantics and whether the change is immediately effective — useful for an agent configuring an environment.

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 already 100% (url, uri format, example), so the baseline is 3; the description adds genuinely new constraints beyond the schema — the node must expose the same /v2/ and /extended/v1/ endpoints as api.hiro.so, and the conventional port 3999. That is useful semantic guidance the schema lacks.

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 ('Point all Stacks API requests at a custom node') and names the default it replaces ('instead of the default Hiro API'), so its effect is unambiguous. It is clearly distinguishable from the get_/delete_stacks_api_url siblings by scope.

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?

Explicitly gives the trigger conditions: run your own stacks-blockchain-api node or use a third-party provider. It stops short of naming the counterpart tools (get_stacks_api_url, delete_stacks_api_url) or stating when not to use it / how to revert, so it misses the top tier.

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