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

With no annotations, the description carries the burden, and it does disclose the key behavioral trait: by default only in-plan streams are returned, while all=True surfaces out-of-plan streams flagged with `available_on`. It does not mention read-only nature explicitly, ordering, or result size limits, so the behavioral picture is only partly complete.

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?

Two compact sentences with the resource and returned fields front-loaded and the parameter behavior second. Nothing is superfluous and no restatement of the name occurs.

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 single-optional-parameter listing tool with an output schema already defining return structure, the description covers scope, default behavior, and the meaning of the one flag. An agent has everything needed to decide to call it and how to set `all`.

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 coverage is 0% for the single `all` parameter, so the description must compensate, and it does: it explains that all=True expands results beyond the plan and adds the `available_on` marker to those rows. That is real semantic value beyond a bare boolean default.

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 leads with a specific verb and resource ('List of data streams') and enumerates the fields returned (name, tier, kind, day range, description), which distinguishes it from siblings such as list_strategies or list_runs. It stops short of explicitly naming a sibling alternative, so it is clear but not fully differentiated.

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?

Usage context is only implied: the tool is for browsing the stream catalog, and the 'all=True' clause suggests when to widen the scope. There is no explicit when-to-use versus when-not-to-use guidance or routing to an alternative tool for stream details.

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