HydraMCP

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 clearly indicates this is a read operation ('List') with no destructive implications, and specifies the scope ('across all providers'). However, it doesn't describe return format, pagination, rate limits, or authentication requirements, leaving gaps in behavioral understanding for a tool with zero annotation coverage.

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 perfectly concise with two sentences that each earn their place. The first sentence states the core purpose, and the second provides crucial usage guidance. There's zero waste, no redundancy, and the information is front-loaded with the most important details first.

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 simplicity (zero parameters, no output schema, no annotations), the description provides adequate coverage of purpose and usage. However, for a tool with no annotations, it should ideally mention more about behavioral aspects like return format or whether results are paginated. The absence of an output schema increases the need for description to explain what the tool returns.

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 tool has zero parameters with 100% schema description coverage, so the schema already fully documents the parameter situation. The description appropriately doesn't waste space discussing nonexistent parameters. It adds value by explaining the tool's purpose and usage context without redundant parameter information, meeting the baseline expectation for zero-parameter tools.

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 ('List all available models') and resource ('models across all providers'), making the purpose immediately understandable. It distinguishes from siblings by focusing on listing rather than querying or comparing models, though it doesn't explicitly name alternatives. The 'Run this first' guidance reinforces its discovery function.

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 explicit context about when to use this tool ('Run this first to see what you can query'), positioning it as an initial discovery step. It implies this should precede using query/comparison tools like ask_model or compare_models, though it doesn't explicitly name these alternatives or specify when NOT to use it.

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