alpaca-mcp-server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool 'replaces' an order, implying mutation, but doesn't clarify if this is destructive (e.g., overwrites existing order), requires specific permissions, has rate limits, or what happens on failure. The constraint 'At least one optional field must be provided' adds some context, but overall, it lacks details on safety, side effects, or response behavior, which is inadequate for a mutation tool.

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 extremely concise with two sentences that are front-loaded and waste no words. It directly states the purpose and a key constraint, making it easy to parse. Every sentence earns its place by providing essential information without redundancy.

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 (8 parameters, nested objects, mutation operation) and the presence of an output schema (which handles return values), the description is minimally adequate. It covers the basic purpose and a constraint, but with no annotations and rich input schema, it should do more to explain behavioral aspects like error handling or idempotency. The output schema reduces the need for return value details, but the description lacks completeness for safe invocation.

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 description coverage is 100%, so the schema already documents all 8 parameters thoroughly. The description adds minimal value beyond the schema by implying that optional fields are for updates, but it doesn't explain parameter interactions or provide additional semantics. Given the high schema coverage, the baseline score of 3 is appropriate, as the description doesn't compensate with extra insights.

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 ('Replaces an existing open order') and the resource ('order'), specifying it's for updates to parameters. It distinguishes from siblings like 'cancel_order_by_id' by focusing on modification rather than cancellation, though it doesn't explicitly name alternatives. The mention of 'open order' provides useful scope, but it could be more specific about what 'replaces' entails compared to other update tools.

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 by stating 'At least one optional field must be provided,' which suggests when to use it (for updating orders) but lacks explicit guidance on when to choose this over alternatives like 'place_stock_order' for new orders or 'cancel_order_by_id' for removal. It doesn't mention prerequisites (e.g., order must be open) or exclusions, leaving usage context somewhat vague.

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