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

Annotations already declare readOnly/openWorld/idempotent/destructive hints, and the description adds substantial value beyond them: it discloses that no arguments select the latest actually-published edition which may not be dated today, instructs using the actual publication time, warns not to claim video is playing/embedded without host confirmation, and clarifies that show figures belong to that edition rather than current markets. These are non-obvious behavioral constraints an agent could not derive from the structured fields.

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?

Front-loaded with the trigger condition, then organized into labeled sections (Selection, Presentation, Evidence). Every sentence conveys a distinct constraint or caveat with no filler, appropriate to the tool's non-trivial behavioral rules.

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 a zero-parameter tool with an output schema (so return values need not be described), the description is complete: it covers selection logic, presentation caveats, and the evidence/edition scoping. An agent has everything needed to invoke it and interpret its results correctly.

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 zero parameters, so the baseline is 4. The description does explain the semantics of the empty-argument call (it selects the latest published edition rather than requiring input), which adds useful meaning, but there are no parameters to document beyond that.

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?

States a specific verb and resource: reading the published Market Update show, its desk briefing or chapters, and gives a concrete user-facing trigger ('What did today's show cover?'). It explicitly distinguishes itself from research_markets, Daily News, arbitrary historical shows, and full archive search, so an agent can tell it apart from siblings without opening schemas.

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?

Provides explicit when-to-use (latest Market Update show/briefing/chapters) and when-not-to-use, naming the alternatives by tool name (research_markets) and content type (Daily News, arbitrary historical show, full archive search). Nothing is left to inference.

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