rate_chart

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

No annotations exist, so the description carries full burden. It discloses the visual output (ASCII chart in terminal), but does not mention side effects, idempotency, rate limits, or handling of missing data. Basic behavioral context but not thorough.

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?

Two sentences, no wasted words. Front-loaded with the core action. Arrow to the point and easy to read.

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 no output schema and moderate complexity, the description covers the basic purpose but omits details like default days, valid range (7-60), terminal width assumptions, or data freshness. Could be more complete.

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 clear descriptions for from/to/days. The description only adds 'over N days', which is redundant. No additional parameter meaning beyond 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 explicitly states 'Render an ASCII line chart of a currency pair's rate history over N days', which is a specific verb+resource pair. It distinguishes from siblings like get_historical_rates (returns data not chart) and get_rate (single value). No ambiguity.

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 for visualizing trends ('Shows trend visually'), but does not provide explicit when-to-use or when-not-to-use guidance compared to siblings like moving_average or correlation_analysis. No exclusions or alternatives listed.

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