list_symbols

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

With no annotations, the description carries the behavioral transparency burden. It does disclose that `as_of` is required and that the call fails without it, and it mentions that the output includes coverage. However, it does not explain what 'coverage' means, how results are ordered, or how invalid dates are handled. Some behavioral context is present, but significant gaps remain.

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 compact and front-loaded: the first sentence states the core purpose, the second gives call context, and the third provides concrete examples plus a required-parameter warning. Every sentence earns its place with no filler.

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 simple one-parameter discovery tool with an output schema, the description covers the essential invocation details: what it does, when to call it, and concrete examples. It is slightly incomplete in not defining 'coverage,' but the output schema likely fills that gap, so the definition is sufficient for effective agent use.

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%, and the parameter `as_of` is already richly described in the schema with point-in-time semantics and a warning about backtesting. The description adds only examples and reiterates that `as_of` is required, which is useful but not a substantial addition beyond the schema.

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 starts with a specific verb and resource: 'List the symbols in the dataset with their coverage.' It clearly distinguishes itself from sibling tools by saying 'Call this first when you do not know which symbols exist,' which positions it as a discovery/introspection tool rather than a data retrieval or analysis tool.

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?

It provides explicit guidance on when to use this tool: 'Call this first when you do not know which symbols exist.' This gives a clear context for invocation, but it does not explicitly name alternative sibling tools or state when not to use it, so it falls just short of a 5.

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