Copilot Money MCP

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

The annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds valuable context about the data source ('local LevelDB cache') and data enrichment ('enriched with ticker symbol and name from the securities collection'), which goes beyond the annotations. However, it doesn't describe behavioral aspects like response format, error conditions, or cache freshness.

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 efficiently structured in two sentences: the first states the core purpose and data characteristics, the second provides filtering guidance. Every word serves a purpose with no redundancy or unnecessary elaboration, making it easy to parse quickly.

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 read-only tool with good annotations and full parameter documentation, the description provides adequate context about what data is returned and how it's sourced. However, without an output schema, the description doesn't explain the structure of the returned performance records, which would be valuable for an agent to understand what to expect from this tool.

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?

With 100% schema description coverage, the input schema fully documents all 4 parameters. The description mentions filtering by ticker symbol or security ID, which aligns with the schema but doesn't add significant semantic value beyond what's already in the parameter descriptions. The baseline score of 3 is appropriate when the schema does the heavy lifting.

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 specific action ('Get per-security investment performance data'), the resource ('structured performance records'), and the data source ('local LevelDB cache'). It distinguishes this tool from siblings like get_investment_prices or get_holdings by focusing on performance data rather than prices, holdings, or other investment-related information.

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 provides clear context for when to use this tool ('Filter by ticker symbol or security ID'), but it doesn't explicitly state when not to use it or name specific alternatives among the sibling tools. The filtering guidance is helpful but lacks explicit exclusion criteria or comparison to similar tools like get_twr_returns.

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