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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true and destructiveHint=false, so safety is covered. The description adds genuinely non-structured context: the HTTP endpoint, plan availability, per-call cost in request units, and that payloads are Turkish JSON with source and `guncelleme` fields. It does not describe freshness cadence (how often values update) or how 'change' is computed, so it goes beyond annotations but not richly.

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?

Front-loaded with the capability and the indicator list, then separated operational facts (endpoint, plans, cost) and the sibling redirect. The 19-item enumeration is long but each entry helps selection, and no sentence is pure filler apart from the redundant 'Read-only' restatement of the annotation.

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 no output schema, the description carries the burden of describing returns and does so: latest value, previous value and change, plus source and `guncelleme` metadata, in Turkish JSON. Combined with endpoint, cost and sibling routing, an agent has everything needed to call it 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 tool takes zero parameters, so there is nothing for the description to clarify; per the baseline rule a 4 applies. The description correctly implies a single global snapshot with no filtering options.

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?

States a specific verb and resource and then enumerates the 19 indicators covered (unemployment, reserves, exports, REER, core inflation B/C, house price index, rent indices, expectations), so an agent can match a user question to this tool without opening a schema. It also draws the boundary against the sibling ekonomi_enflasyon for headline CPI and the legal rent cap.

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?

Explicit routing rule: use this tool for the listed indicators, but use ekonomi_enflasyon for headline CPI and the legal rent increase cap. It also states availability (all plans including free) and cost (1 request unit), which tells the agent when the call is cheap enough to make.

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