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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable context: billing at $0.006 per page, empty-list behavior for users with no live stories, and return shape by referencing tiktok_user_videos. It does not cover auth or rate limits, but the added cost and return details exceed the annotation baseline.

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 the core action. It efficiently includes return shape, empty-result behavior, and billing cost without redundancy. Every sentence earns its place.

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?

Covers purpose, cost, empty-result behavior, and return shape via reference to tiktok_user_videos. With annotations covering safety and a 100% schema, the description is nearly complete. Missing details like auth requirements or rate limits are minor for a read-only endpoint.

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%, so all five parameters are fully documented in the schema. The description only repeats the 'provide exactly one of username, user_id, or url' constraint already present in the schema. Baseline 3 applies 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 and resource: 'Get a TikTok user's currently live stories (24-hour posts)'. It distinguishes itself from tiktok_user_videos by specifying stories, and from generic video tools by the 24-hour scope. An agent can identify the resource 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?

Provides clear context that this is for 24-hour stories, but does not explicitly name when to use it instead of alternatives like tiktok_user_videos or search_tiktok. The 'provide exactly one' instruction is usage guidance but not alternative routing. Usage is implied rather than stated.

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