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

Annotations already declare readOnlyHint=true, openWorldHint=true, and idempotentHint=true, covering safety and idempotency. The description goes well beyond by disclosing the size risk ('Description and profile overview can together run to tens of KB'), the outline fallback when over budget, the guarantee that 'Nothing is truncated on any path,' and the archive mode's pagination semantics. This provides rich behavioral context that annotations cannot express.

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 description is dense but every sentence earns its place. It front-loads the primary purpose, then explains usage context, then details the selectors and edge cases. The structure is clear: main fetch, then two alternative modes, then size behavior. No filler or redundancy; it is long only because it packs precise, non-repeating information.

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 tool's complexity (two selectors, pagination, outline fallback, size constraints), the description covers all necessary operational aspects. It explains the archive page response structure (identity, list, total/shown/offset, next offset), the sections requirement of exact names from the outline, and the self-contained nature of calls. An output schema exists, so return-value details are not needed; the description fully equips an agent to invoke the tool correctly in all documented scenarios.

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 each parameter (id, archive, sections) is already documented with types, defaults, and descriptions. The description adds critical meaning beyond the schema: it explains the mutual exclusivity of archive and sections, the exact behavior of each selector (archive replaces the record, sections slices it), and how the outline response supplies section names for the sections parameter. This is more than the baseline 3, though the schema already carries heavy weight.

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 states a specific verb ('Fetch') and resource ('disaster record by ReliefWeb numeric ID') and enumerates the returned content (description, affected countries, GLIDE number, profile overview, key content links, active appeals/response plans). It clearly differentiates from sibling search tools by prescribing use after reliefweb_search_disasters and by introducing the archive selector, which is unique to this tool.

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 directs 'Use after reliefweb_search_disasters to retrieve full details.' It further explains when to use the archive parameter (to retrieve archived entries not in the record) and when the sections parameter is needed (to target specific parts or handle oversized records). It also states that a record over the budget returns a section outline, giving a clear contingency path. No alternative tool is named, but the usage context is unambiguous.

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