get_market_data

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

It discloses caching with SQLite, the permission requirement, and partial error handling. It also mentions TTL override. These are important behaviors not in the schema or 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?

Three sentences, front-loaded with the primary action, then requirement, then error behavior. No wasted words.

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?

It explains key behaviors and constraints, but without an output schema, it doesn't specify the full return shape. It gives enough for basic use, but could mention what the response contains beyond errors.

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 only documents one of three parameters, and the description adds details for tickers (1-50) and cache_ttl_minutes (override), but leaves 'include' unexplained. Since coverage is low, it partially compensates but not fully.

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 the action (fetch quotes and/or fundamentals), the source (brapi.dev), the range (1-50 tickers), and a prerequisite (outbound_enabled=true). It distinguishes this from other tools like get_crypto_quote by focusing on general market data and multiple tickers.

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?

It provides specific usage conditions: requires outbound_enabled=true and explains partial failure behavior. It doesn't explicitly contrast with alternatives but the condition and multi-ticker scope give enough guidance.

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