get_watchlist_changes

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

Annotations already declare readOnlyHint and destructiveHint false. The description adds valuable behavioral context: it returns only changed records, requires a Plus or Pro plan for stability metadata, and works relative to the last pipeline run. This goes beyond annotation coverage.

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 longer but every sentence contributes: core function, supported comparisons, metadata plan requirement, and guidance versus sibling tools. It is front-loaded and well-structured, though slightly verbose.

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's complexity and existing output schema, the description covers the data scope, use cases, and plan limitations. It explains why this tool should be chosen over get_watchlist and mentions the day-over-day only limitation of the sibling's notable_changes array.

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 coverage is 100% with the enum described. The description adds meaning by explaining 'daily' as day-over-day and 'weekly' as week-over-week, and notes the default. This supplements the schema without repeating it.

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 it gets field-level state changes for watchlist tickers since the last pipeline run, with a specific verb and resource. It also distinguishes itself from get_watchlist by emphasizing it returns only deltas, not full summaries.

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?

Explicitly provides when-to-use and when-not-to-use guidance: prefer it over get_watchlist for monitoring changes, use get_watchlist for current full state, and notes it is the only way to get week-over-week changes. Names the alternative tool directly.

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