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

Annotations only declare readOnlyHint and openWorldHint; the description adds substantial operational context the agent cannot get elsewhere: required USAJOBS_API_KEY and USAJOBS_EMAIL, an explicit 503 failure mode when missing, a $0.002 USDC per-successful-call price, the x402 payment rails (Base, Solana, Arc), and the fact that failed calls are not charged. That billing-on-failure clause is exactly the kind of consequence an agent needs before calling.

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 resource and source are front-loaded in the first clause, with prerequisites, failure mode and pricing following in priority order. It is dense but every clause carries a distinct operational fact; only the field enumeration is mildly redundant given the 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 two-parameter read tool with an output schema, the description covers what the schema can't: credentials, failure behavior, and cost model. Minor gaps remain — no mention of result ordering, pagination/limit interplay, or rate limits — but nothing critical to calling it correctly is missing.

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 keyword and limit are already documented with an example and a range. The description lists output fields but adds no meaning about the search parameter itself (matching behavior, multi-word handling, federal-specific query syntax), so it neither compensates for nor extends the schema.

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 resource and scope — 'US federal job openings from the official USAJOBS Search API' — and enumerates returned fields (title, agency, location, pay range, closing date, link). The 'US federal' qualifier plus the named API source is enough to distinguish it from the many generic job-board siblings without opening either schema.

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 'US federal job openings' and the official-API sourcing, which tells an agent this is the authoritative federal source rather than a general board. However, it never explicitly says when to choose this over siblings like jobs_governmentjobs or jobs_indeed, nor any exclusions (e.g., no state/local roles, no contractor listings).

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