fetch_data

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

With no annotations, the description carries the full burden. It discloses the monetary side effect (priced per call, spends prepaid credits from FETCHER_API_KEY) and the live-data behavior. It could say more about error handling or response shape, but the key behavioral costs are clear.

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?

Every sentence earns its place: cost warning, purpose, parameter-passing rule, follow-up guidance, and configuration alternative are all packed in without fluff. The essential 'Paid' warning is front-loaded.

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 generic endpoint-fetching tool with only two parameters and no output schema, the description plus schema covers usage, cost, authentication, and the recommended describe_endpoint step. A more explicit statement about return format/errors would increase completeness, but the guidance to call describe_endpoint mitigates that 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?

Schema description coverage is 100%, so the schema already documents both parameters. The description reinforces that path and query parameters go together in `params`, which matches the schema, but it does not add substantial new semantic information beyond that.

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 ('Fetch'), a resource ('live data from any fetcher.sh endpoint'), and clearly differentiates from siblings like search_endpoints and describe_endpoint, which discover/describe endpoints rather than execute 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?

Gives clear context on when to call this tool, including the paid nature and a direct pointer to describe_endpoint when unsure. It also mentions the alternative of configuring FETCHER_SERVICE for named per-endpoint tools, though it does not explicitly enumerate all sibling comparisons.

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