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

The annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds useful context that the call is free and should be made once at the start, which goes beyond the structured annotations without contradicting them.

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 definition is compact and front-loads the metadata categories before the usage instruction. The first sentence is dense with enumerated items, but every item earns its place by clarifying what the agent will receive.

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?

With an output schema present and zero parameters, the description need not explain return value structure. It still provides enough content detail and timing guidance for an agent to call this metadata tool correctly once at startup.

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 takes no parameters, so the schema and description do not need to explain argument semantics. The baseline score of 4 applies because the description correctly implies a no-argument metadata retrieval.

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 identifies the tool as returning FILTRIX API definitions and limits, and enumerates the specific metadata categories it covers: backtest outcomes, operators, filter limits, quotas, free calls, and historical date range. This distinguishes it from the operational sibling tools without needing to name one explicitly.

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 instruction to 'Call once at the start; it is free' gives clear timing guidance and a cost-related incentive. It does not describe when not to call it or name alternatives, but there is no sibling tool competing for this metadata purpose.

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