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

Annotations already establish read-only and open-world behavior, yet the description adds substantive context the annotations lack: it requires the operator's JOOBLE_API_KEY, costs $0.002 USDC per successful call via x402 on Base/Solana/Arc, and that failed calls are not charged. That auth-and-billing disclosure materially informs invocation; rate limits and pagination behavior are the only notable omissions.

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?

Three compact sentences: purpose first, then coverage constraint, then auth and pricing. Every sentence carries information, though the output-field enumeration is somewhat redundant given an output schema exists.

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 five-parameter read-only search with full schema coverage and an output schema, the description supplies the non-obvious operational facts an agent needs: API key requirement, US-only coverage, and per-call cost including the failure case. Only rate limits and result-volume expectations are left unaddressed.

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 page, radius, and salary semantics are already fully documented in the input schema; the description adds no parameter-level detail. The list of fields it recites (title, company, salary text, etc.) are return values, not inputs, which risks being misread as parameter guidance.

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 ('Job search on Jooble's aggregator through its official REST API') and enumerates the returned fields, so the agent knows exactly what it gets back. It identifies the provider clearly enough to separate it from siblings like jobs_indeed or jobs_multi_job_board, though it never explicitly says how it differs from those other aggregators.

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 is implied rather than stated: it is a keyword+location job search, and the note that a jooble.org key covers US listings only hints at when it is appropriate. There is no explicit 'use this instead of X' routing and no stated exclusions beyond the geographic limitation.

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