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

Annotations already declare this a read-only, idempotent, non-destructive, closed-world call, so the safety profile is covered. The description adds a genuinely useful behavioral fact beyond that: matching is simple word matching against show names and episode titles only, not descriptions or semantic matching — which tells the agent what will silently fail to match.

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?

Three sentences, front-loaded with scope and matching mechanics before the examples. The example questions carry real disambiguating value, though the phrasing is slightly chatty and the hours behavior is left entirely to the schema.

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 two-optional-parameter read tool with a full schema and clear annotations, this covers what is needed to call it correctly. The one gap is return shape — with no output schema, the description only loosely says it produces 'a guide to everything on now and coming up soon' without indicating whether results include times, stations, or episode detail.

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 100%, so both parameters are already documented with types, bounds, and defaults. The description still adds meaning beyond the schema: which fields 'topic' is matched against, and the semantic consequence of omitting it (an all-stations guide rather than an empty search).

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 gives a specific verb and scope: it searches every station for what's on now and in the next few hours, keyed on topic words. That is clearly different from a plain schedule listing (whats_on) or a per-show lookup, though no sibling is named explicitly, so it lands at 4 rather than 5.

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 concrete usage examples ('is anything about birds on?', 'when's the next PBS News Hour?') and states the topic-omitted case (a guide to everything on now and coming up). It stops short of naming alternatives or stating when NOT to use it, so it is clear context rather than a full routing rule.

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