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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety. The description adds content context (what data is returned) but does not disclose any additional behavioral traits such as pagination, default ordering, or how the limit parameter works. With annotations covering the core behavior, a 3 is appropriate.

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, front-loaded with the core data content and a clear usage directive. No redundant information; every sentence earns its place.

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 simple query tool with three parameters, all documented in the schema, the description covers purpose, content, and usage. It does not specify the output format, but since there is no output schema and the tool is read-only, the description is sufficiently complete for an agent to call it correctly. A minor addition about default row count or sorting would be nice, but not essential.

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 (limit, years, country) has a basic description. The tool description does not add meaning beyond that—it doesn't explain the format of years or country codes, or provide examples beyond the schema's own example. The baseline of 3 applies because the schema already documents the parameters.

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 names a specific verb ('financing', 'budget') and a clear resource (national TB programme financing by country and year), with the specific data fields (total TB budget, cost per patient for DS and MDR-TB, patients expected). It clearly distinguishes from sibling tools like who_tb_estimates and who_tb_notifications, which cover different aspects.

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 explicitly states 'Use for questions about TB programme funding and the cost of TB treatment,' giving a clear use case. It does not explicitly list exclusions or alternatives, but the context is sufficient for an agent to know when to choose this tool over siblings.

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