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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds valuable context beyond that: the data source (UN OCHA HDX HAPI), the license (CC BY 4.0), and the fact that no authentication is required. These details help an agent understand what calling the tool entails without contradicting the annotations.

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 three sentences: the purpose, the filters, and the data provenance/license/auth. Every sentence carries useful information and the core action is front-loaded. There is no fluff or repetition.

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?

With a rich output schema, comprehensive annotations, and 100% parameter descriptions, the description covers the remaining context an agent needs: source, license, auth, and filter dimensions. Nothing essential is missing for correct invocation, especially since the output schema handles return value documentation.

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 baseline is 3. The description repeats some filter names (location_code, sector_name, org_name, admin1_name, admin_level) but does not add any information beyond what the schema already provides. It also does not clarify limit/offset or the location_name alternative, though these are fully described in 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?

The description opens with a specific verb and resource: 'Get "who's doing what, where" (3W) humanitarian response data' and then details exactly what the data contains (organizations, sectors, locations). It clearly distinguishes itself from sibling HDX HAPI tools like humanitarian_needs or food security IPC by naming the unique domain of operational presence.

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?

The description provides strong context for when to use the tool: it is for 3W operational presence data, and it enumerates the available filters. However, it does not explicitly name sibling alternatives or state when not to use it, so it falls short of full guidance but remains clear enough for an agent to select it correctly.

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