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

Even with readOnlyHint=true and openWorldHint=true, the description adds meaningful behavioral context: the data source, temporal coverage (2009–October 2024), the station requirement, pagination/boundedness, and the important caveat that most station monitoring ended in October 2024. This goes well beyond the annotations and helps the agent set expectations.

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 front-loaded with the core search capability and then moves through station requirements, operator syntax, and the critical October 2024 caveat. It is dense but not bloated; the only mild cost is some repetition of schema-documented details like the station requirement and date range.

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 rich input schema, an output schema, and annotations, the description covers the essential non-obvious facts an agent needs: the need to supply a station, the supported in-query operators, the data's end date, and the recommendation to verify station coverage. Return values are already handled by the output schema, so no further description is needed.

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 schema thoroughly documents all 10 parameters, including the station requirement, operator syntax, date formatting, and normalization behavior. The description largely repeats or re-emphasizes what the schema already states rather than adding new parameter-level meaning, so the baseline of 3 is appropriate.

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 names a specific verb ('Search'), a specific resource ('US television news closed captions'), and a clear output ('bounded, paged per-station time series'). It also distinguishes itself from sibling tools by focusing on search over captions and by explicitly invoking gdelt_list_tv_stations, so an agent can tell it apart without opening the schema.

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 description gives clear operational context: the TV API requires at least one station, stations can be supplied via the stations parameter or an in-query operator, and gdelt_list_tv_stations should be used to verify active date ranges before querying recent events. It does not explicitly list exclusions or alternatives such as preferring gdelt_get_tv_clips for clip retrieval, so it falls just short of full 'when-not' guidance.

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