alpaca-mcp-server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that 'loc' is required and should be set to 'us', which adds some operational context, but it fails to describe key behaviors such as rate limits, authentication needs, error handling, or what the output looks like (though an output schema exists). For a tool with no annotations, this leaves significant gaps in understanding its behavior.

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 and front-loaded, consisting of just two sentences that directly state the purpose and a key parameter guideline. There is no wasted language, and every sentence serves a clear purpose, making it efficient and easy to parse.

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 low complexity (2 parameters, no nested objects) and the presence of an output schema (which handles return values), the description is mostly complete. It covers the basic purpose and a critical parameter note. However, with no annotations, it could benefit from more behavioral context like rate limits or auth requirements, but the output schema reduces the need for extensive detail.

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 description coverage is 100%, so the schema already documents both parameters thoroughly. The description adds minimal value by emphasizing that 'loc' is required and should be set to 'us', but this is somewhat redundant with the schema's required field and enum. It does not provide additional syntax or format details beyond what the schema offers, so it meets the baseline for high schema coverage.

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 tool's purpose: 'Returns the latest trade for one or more crypto symbols.' It specifies the verb ('returns') and resource ('latest trade for crypto symbols'), making it easy to understand. However, it does not explicitly differentiate from sibling tools like 'get_crypto_trades' or 'get_crypto_latest_quote', which could cause confusion, so it's not a perfect 5.

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 some usage guidance by stating 'The loc parameter is required — always set loc to "us".' This implies a specific context for parameter usage but does not explain when to use this tool versus alternatives like 'get_crypto_trades' or 'get_crypto_latest_quote'. It lacks explicit when/when-not instructions or named alternatives, so it's only implied usage.

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