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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds a genuinely useful negative constraint — 'never fetches or returns video media' — which tells the agent this is metadata-only and prevents assumptions about media retrieval. It stops short of noting failure behavior for non-canonical URLs.

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?

One sentence, front-loaded with the verb and resource, then the explicit exclusion. Zero waste and nothing to trim.

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?

An output schema exists, so return-value explanation is unnecessary, and the single required parameter is fully documented. The description covers the returned fields and the media exclusion, but gives no hint about behavior on invalid or non-canonical URLs, which is the main remaining gap for a one-parameter fetch tool.

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% for the single url parameter, so the schema already documents it. The description reinforces the 'canonical' requirement but adds no format or syntax detail beyond that. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (fetch) and resource (metadata from a canonical NDTV video URL) and enumerates the fields returned (title, description, date, duration, thumbnail). It implicitly separates itself from sibling list tools like ndtv_videos and ndtv_latest_videos by requiring a single canonical URL, though it never names those siblings explicitly.

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?

There is no explicit when-to-use guidance or stated alternative. The phrase 'canonical NDTV video URL' implies the tool is for single-item detail lookup and that listing tools should be used first, but the agent must infer this rather than being told.

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