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

The annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the description does not need to repeat those. It adds useful context beyond the annotations by stating that no authentication is required, and it cites the data source (HDX HAPI, UN OCHA) and license (CC BY 4.0). These are valuable behavioral disclosures not present in the structured metadata.

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 two sentences long and front-loads the core purpose, then states the filters and data provenance. Every sentence serves a purpose with no redundant or fluffy wording. It is appropriately compact for a tool of this complexity.

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 has an output schema, annotations, and a well-covered parameter schema, the description is nearly complete. It covers the what, the filters, the data source, and auth. The only missing piece is explicit guidance on when to choose this over other population tools, but that is arguably covered under usage guidelines. The description provides enough for an agent to call the tool correctly.

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 input schema provides 100% coverage with descriptions for all 8 parameters, including enums for gender and admin_level. The description merely lists some of the filter parameters without adding new semantic meaning beyond what the schema already documents. It does not explain any parameter interactions or format expectations that the schema lacks, so it stays at the baseline of 3.

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 clearly states the tool retrieves baseline population demographics broken down by gender and age range, and specifies it applies to countries or subnational admin areas. It names the resource and the verb 'Get', making the purpose unmistakable even among many population-related siblings. It also lists the key filter parameters, which distinguishes it from other HDX tools.

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 gives clear context: it is a read-only query for baseline population data from the HDX HAPI, and it enumerates the filter dimensions. However, it does not explicitly state when to prefer this tool over other population data sources (e.g., census.data.population or abs.demographics.population), nor does it mention exclusions. The implied usage is clear but not explicitly differentiated from alternatives.

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