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

The annotations already mark readOnlyHint, openWorldHint, and idempotentHint, so the description correctly does not repeat those. It adds a crucial behavioral detail: 'Reaches expired postings as well as open ones.' It also fully discloses the response-budget fallback behavior (section outline with byte sizes and the need to re-call with sections) and explicitly guarantees that nothing is truncated on either path. This is thorough, non-redundant behavior disclosure.

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 dense sentences, each earning its place: the first establishes purpose and contents, the second gives usage context, the third covers the edge case and its workaround. No filler or repetition. The key differentiator (full details vs. summaries) is front-loaded, and the response-budget behavior is neatly packaged at the end. Efficiency without sacrificing completeness.

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?

Given the simple two-parameter tool, an output schema, and rich annotations, the description covers all necessary facets: purpose, usage sequencing, edge-case handling, and parameter semantics. It explicitly ties the 'sections' parameter to the outline response rather than leaving the agent to guess. Nothing the agent needs to invoke this tool 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?

The schema covers both parameters at 100%, but the description enriches them substantially. For 'id', it notes it comes from a prior search result. For 'sections', it explains the outline-driven naming, the omission behavior for full record, the inclusion of identity metadata, and the self-contained re-fetch mechanics. This goes well beyond the baseline schema descriptions and gives the agent concrete, actionable parameter semantics.

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?

The description opens with a specific verb ('Fetch') and resource ('a job posting by ReliefWeb numeric ID'), enumerating the contained content (full vacancy description, application instructions, dates, hiring organization, location, taxonomy). It explicitly contrasts with the sibling reliefweb_search_jobs, which returns only summaries, so an agent can immediately distinguish this tool from its search counterpart without inspecting schemas.

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?

It states exactly when to use this tool: 'Use after reliefweb_search_jobs, which returns summaries without the description or application instructions.' This names the alternative and the condition that selects this tool. It also explains the workflow for the over-budget case (outline response then re-call with sections), giving the agent concrete steps to follow.

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