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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds a meaningful behavioral fact — the result is capped at the first 15 cards — but says nothing about ordering, freshness, or what happens with an invalid slug.

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?

A single front-loaded sentence with no filler; the count, scope, and prerequisite are all packed into one clause.

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?

With annotations covering the safety profile, an output schema covering the return shape, and a fully documented parameter, the description supplies what is missing (the 15-item cap and slug provenance). Only minor gaps remain, such as ordering or error behavior.

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 itself enumerates all documented section slugs. The description only restates that the value comes from timeslive_sections, adding no syntax or format detail beyond the schema, so the baseline 3 applies.

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), resource (TimesLIVE story cards), and scope (first 15, one section). It also names the sibling timeslive_sections as the source of the slug, which cleanly distinguishes it from timeslive_news and timeslive_article.

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?

Gives clear context: the section slug must come from timeslive_sections, establishing a prerequisite workflow. It does not explicitly say when to prefer this over timeslive_news or timeslive_sections, but the coupling to a section slug makes the intended use unambiguous.

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