Copilot Money MCP

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

Annotations declare readOnlyHint=true, but the description adds valuable behavioral context: it explains the cache auto-refresh interval (5 minutes) and that it returns updated cache info after refresh. This goes beyond the annotation's safety profile by detailing operational behavior and output.

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 concise sentences, each earning its place: first states purpose, second provides usage guidelines, third adds behavioral context and output info. No wasted words, and key information is front-loaded.

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 zero-parameter tool with readOnlyHint annotation but no output schema, the description is complete: it explains purpose, usage, behavioral traits (auto-refresh interval), and return value ('updated cache info'). No gaps given the tool's simplicity.

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 0 parameters and 100% schema description coverage, the baseline is 4. The description reinforces that no inputs are needed, aligning with the empty schema, and adds no extraneous parameter details.

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 ('refresh the in-memory cache') and resource ('data from the local Copilot Money database'), distinguishing it from sibling tools that primarily retrieve data rather than update cache state. It goes beyond just restating the name by explaining what 'refresh' entails.

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 states when to use this tool: 'when the user has recently synced new transactions' or 'when you suspect the cached data is stale.' It also provides when-not guidance by mentioning the cache auto-refreshes every 5 minutes, helping avoid unnecessary calls.

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