Metro İstanbul hatları ve istasyonları

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

Annotations already declare readOnlyHint and openWorldHint. The description adds valuable behavioral context by identifying the source as the İBB Open Data Portal and warning that service times can change. This helps agents avoid treating the data as immutable and clarifies the external dependency, without contradicting 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 compact but information-dense, front-loading the resource and main outputs. The Turkish and English repetition is minor and each sentence serves a purpose: detailed field enumeration, a quick English gloss, and a source/volatility caveat. It is structured well for agent consumption.

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 read-only tool with one optional parameter and an existing output schema, this description is complete. It explains both invocation modes, the returned content, the data source, and the possibility that schedules may change. No essential information for correct usage is missing.

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 schema already covers the `hat` parameter at 100% with examples, so a baseline of 3 is appropriate. The description adds further value by giving extra example line codes (M1A, M5, F1) and by explaining the conditional behavior: supplying `hat` triggers station-level detail. This is meaningful semantic enrichment beyond 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 clearly identifies the resource as Istanbul metro lines and stations wire, and enumerates the returned fields: route name, first/last train times, active status, ordered stations, coordinates, accessibility counts, and amenities. It distinguishes itself well from the sibling tool ibb_metro_duyurular by focusing on line/station data rather than announcements.

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 implies usage: without `hat`, line-level data is returned; with `hat`, the station list for that line is provided. However, it does not explicitly state when to prefer this tool over alternatives or provide any exclusion criteria, leaving some selection judgment to the agent.

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